One advantage of using loop start over ground start is that:

A.
It reduces the number pairs between the end device and the PBX.

B.
It reduces glare between the end device and the PBX.

C.
It reduces connection time.

D.
None of the above

Explanation:
Another advantage of groundstart signaling is the ability for incoming calls (network -> CPE) to seize the outgoing channel, thereby preventing a glare situation