正解：

See the Explanation below for complete solution.
Explanation:
You must create these 3 subaccounts inside the Human Resources directory:
EU HCM Dev
EU HCM Test
EU HCM Prod
Important:
Replace #### with your global account number
Enter names, descriptions, and subdomains exactly
EU HCM Prod must be marked as used in production
Task 3 - Create Subaccounts with Default Provider and Region
Before You Start
Log in to the SAP BTP Cockpit.
Open the correct Global Account.
Go to Directories.
Open the Human Resources directory.
Why this matters:
All 3 subaccounts in this task must be created inside Human Resources. If you create them anywhere else, the result will be incorrect.
Step 1 - Open the Human Resources Directory
What to do
In the left menu, choose Directories.
In the list, select Human Resources.
Explanation:
This is the parent directory where the required HR subaccounts must be created.
What to verify
You should now be inside the Human Resources directory.
Step 2 - Start Creating EU HCM Dev
What to do
Inside Human Resources, open Subaccounts.
Click Create → Subaccount.
Explanation:
This opens the form to create the first HR subaccount.
Step 3 - Enter Values for EU HCM Dev
What to do
Enter the following:
Display Name / Name: EU HCM Dev
Description: Human Resources Development
Subdomain: btpops####-eu-hcm-dev
Set the region as:
Cloud Provider: Amazon Web Services (AWS)
Region: Europe (Frankfurt)
Technical Region / Environment: cf-eu10
Then click Create.

Explanation:
This creates the development subaccount for HR and defines the required provider and region.
This first subaccount is important because it will be used as the source subaccount for the next two subaccounts.
What to verify
After creation, you should see:
EU HCM Dev
under the Human Resources directory.
Step 4 - Confirm EU HCM Dev Exists
What to do
Check the subaccounts list in Human Resources.
Explanation:
You must make sure EU HCM Dev is available before you create the next subaccounts, because both EU HCM Test and EU HCM Prod must use it as the source subaccount.
What to verify
You should see:
EU HCM Dev
If it is missing, create it correctly before moving on.
Step 5 - Start Creating EU HCM Test
What to do
Still in the Human Resources directory, click Create → Subaccount again.
Explanation:
This opens the form for the test subaccount.
Step 6 - Enter Values for EU HCM Test
What to do
Enter:
Display Name / Name: EU HCM Test
Description: Human Resources Testing
Subdomain: btpops####-eu-hcm-test
Then select:
Source Subaccount: EU HCM Dev
Then click Create.

Explanation:
This creates the testing subaccount by using EU HCM Dev as the source subaccount.
This helps keep the configuration aligned with the development subaccount.
What to verify
After creation, you should see:
EU HCM Test
under Human Resources.

Step 7 - Start Creating EU HCM Prod
What to do
In Human Resources, click Create → Subaccount once more.
Explanation:
This opens the form for the production subaccount.
Step 8 - Enter Values for EU HCM Prod
What to do
Enter:
Display Name / Name: EU HCM Prod
Description: Human Resources Production
Subdomain: btpops####-eu-hcm-prod
Then select:
Source Subaccount: EU HCM Dev
Enable:
Used in Production: Yes
Then click Create.
Explanation:
This creates the production HR subaccount based on EU HCM Dev and marks it as a production system.
The production setting is mandatory here.
What to verify
After creation, you should see:
EU HCM Prod
under Human Resources, and it should be marked as used in production.

Final Expected Result for Task 3
Inside the Human Resources directory, you must have these 3 subaccounts:
1. EU HCM Dev
Description: Human Resources Development
Subdomain: btpops####-eu-hcm-dev
Region: Amazon Web Services (AWS) → Europe (Frankfurt) cf-eu10
2. EU HCM Test
Description: Human Resources Testing
Subdomain: btpops####-eu-hcm-test
Source Subaccount: EU HCM Dev
3. EU HCM Prod
Description: Human Resources Production
Subdomain: btpops####-eu-hcm-prod
Source Subaccount: EU HCM Dev
Used in Production: Yes

Common Mistakes to Avoid
1. Creating the subaccounts in the wrong directory
All 3 must be created inside:
Human Resources
Not under:
Global Account
Americas
Eurasia
Partner
2. Wrong subdomain values
Use exactly:
btpops####-eu-hcm-dev
btpops####-eu-hcm-test
btpops####-eu-hcm-prod
Only replace #### with your global account number.
3. Wrong region for EU HCM Dev
It must be:
Amazon Web Services (AWS)
Europe (Frankfurt)
cf-eu10
4. Wrong source subaccount
For both:
EU HCM Test
EU HCM Prod
you must select:
EU HCM Dev
5. Forgetting the production flag
For EU HCM Prod, make sure:
Used in Production is enabled