Which form of SONET switching requires the exchange of the K1 and K2 bytes between adjacent multiplexer and/or cross-connect locations for switching to occur properly?

Which form of SONET switching requires the exchange of the K1 and K2 bytes between adjacent multiplexer and/or cross-connect locations for switching to occur properly?

A.
Unidirectional

B.
1+1

C.
Path Level

D.
Line Level