🔍 Key Concepts

• BFEC vs SFEC: Think about what the first letters "B" and "S" usually mean in communications (e.g., broadcast vs selective/single). • FEC (Forward Error Correction) vs ARQ (Automatic Repeat reQuest): One is typically one-way with no return path needed, the other usually implies two-way handshaking. • Maritime digital selective calling / data systems often distinguish between all-station calls, individual station calls, and two-way sessions.

💭 Think About

• Ask yourself: If "B" indicates a type of call that goes to many or all stations, which choice places that first element (BFEC) as a one-way to all stations event? • If "S" indicates a call to a particular or single station, where in the options is the middle element (SFEC) treated as one-way to a single station? • ARQ protocols require acknowledgments and re‑transmissions. Which listed communication type clearly involves a two-way exchange rather than simple broadcast?

✅ Before You Answer

• Match BFEC with the option that treats it as a one-way, all-stations type communication. • Match SFEC with the option that treats it as one-way to an individual/single station rather than to all stations or two-way. • Confirm that ARQ is aligned with a two-way communication mode in the sequence you pick.