Why do you use APIs? (2)

Why do you use APIs? (2)
A . To connect your SAP S/4HANA Cloud system to other systems
B. To integrate apps in your SAP S/4HANA Cloud System with SAP Cloud Platform
C. To enhance pre-delivered applications with custom fields for you SAP S/4HANA Cloud system
D. To create a data definition for extending a CDS view in your SAP S/4HANA Cloud system

Answer: A,B