In Cisco ACI, contracts govern which two types of endpoint group communications? (Choose two.)
A. between ACI fabric application EPGs (fvAEPg), both intratenant and intertenant
B. between ACI fabric application EPGs and Layer 2 internal networks
C. between ACI fabric application EPGs and Layer 3 external outside network instance EPGs (l3extInstP)
D. strictly between ACI fabric out-of-band EPGs
