To make a call to another vessel requesting TELEX communications regarding important company business, the GMDSS operator should:

Correct Answer: Option A — Select Routine priority, enter other vessel's MMSI, specify legal alternate frequency, F1B emission and transmit the properly formatted DSC call.

Routine DSC calls for ship-to-ship communications require the caller to specify the MMSI of the target vessel and the intended working frequency. Per ITU-R M.541, the operator must select the appropriate priority and emission mode (F1B for NBDP/TELEX) to ensure the receiving station can correctly tune to the assigned channel.