The correct answer is C.
OBJ-5.2: You may not know all the details involved in this question, but that is ok. Start with what you do know. The question talks about an OC12 connection. What kind of cable is used with that? An OC-12 is a fiber optic cable. Based on that, you know the only one of these options that has anything to do with a fiber cable is an OTDR (Optical Time-Domain Reflectometer). The other options apply only to copper cables (like Cat 5e, Cat 6a, and T-1).