Which of the following is one of the connections required between a computer and a transceiver to operate digital modes?

Answer: C. Computer “line in” to transceiver speaker connector

The computer must hear what the radio receives. Received audio comes out of the transceiver's speaker connector and goes into the computer's "line in". So computer "line in" to transceiver speaker connector is correct. Audio does not key push-to-talk.

Tip: Speaker out feeds computer line in.