Regarding the connection of different circuit boards and boards of OTN equipment, which of the following statement is correct? (Multiple choice)
A . TN12ND2 and TN12NS2 can be connected in AFEC mode
B . TN12ND2 and TN11ND2 can be connected in AFEC mode
C . TN12ND2 and TN52ND2 can be connected in AFEC mode
D . TN12ND2 and TN52/53/54/57NQ2 can be connected in AFEC mode
Answer: CD