Which of the following can you use to connect external systems and applications to SAP Business ByDesign? Note: There are 3 correct answers to this question.

Which of the following can you use to connect external systems and applications to SAP Business ByDesign? Note: There are 3 correct answers to this question.
A . Custom OData services
B . IDoc interfaces using RFC
C . Web service APIs (SOAP)
D . DCOM interfaces
E . OData APIs for reports and data sources

Answer: A,B,C