Hi,
If I understand correctly, In some cases you want to send the request to component C and in few cases respond from component B itself,
Case1: (component A) <----req-rsp----> (component B[Virtual Service])
component A will get the response from Virtual Service B, Here Virtual Service C is not required since you have the option to configure component C response in Virtual Service B
Case2: (component A) <----req-rsp----> (component B[use live invocation in VS ]) <----req-rsp----> (component C)
component A will get the response from component C, Here Virtual Service B will act as a Gateway
Best Regards,
Venkat Yedida