Several users from the same building are reporting connectivity issues. The SFP at that building’s IDF
switch is showing a link light, but there is no link light to the corresponding switch’s SFP at the MDF.
Which of the following is the MOST likely cause?

A.
A crossover cable is being used.

B.
DB loss is too high on all strands.

C.
Only TX or RX strand is working.

D.
TX and RX are reversed.