Which of the following API types does SAP recommend to use to achieve clean core...

For clean core integrations in SAP S/4HANA (minimizing custom code):

SOAP (A): SAP recommends SOAP APIs for robust, secure integrations (e.g., enterprise services), supporting clean core by leveraging standard interfaces.

OData (D): OData is the preferred RESTful API type for S/4HANA, enabling flexible, standard integrations (e.g., via SAP Gateway), a cornerstone of clean core.

RFC (B): Remote Function Calls are legacy and less favored for clean core due to tight coupling.

IDoc (C): IDocs are traditional EDI-focused, not prioritized for modern clean core integrations.

Thus, "SOAP" and "OData" are the correct answers.References: SAP Help Portal - "Integration APIs in S/4HANA"; SAP S/4HANA Developer Guide - "Clean Core APIs".