What does enabling the SFAPI Web service feature do?

What does enabling the SFAPI Web service feature do?
A . Allows SAP SuccessFactors Employee Central Payroll to retrieve employee data through ^ CompoundEmployee
B . Allows SAP SuccessFactors Employee Central Payroll to retrieve data through the People U Profile
C . Allows SAP SuccessFactors Employee Central to retrieve data through the People Profile
D . Allows SAP SuccessFactors Employee Central to retrieve employee data through ^ CompoundEmployee

Answer: D