What character(s) are transmitted to switch control from a station currently transmitting, over to the receiving station during ATOR communications in the ARQ mode?

Correct Answer: Option A — +?

The '+?' sequence is used in ARQ mode to invite the receiving station to transmit. It effectively switches the direction of the traffic flow, allowing the vessel or the coast station to take control of the link to send data or instructions, ensuring orderly communication between the two connected stations.