Which statement about handsets is true?

• A. Handsets are not designed for long-term communication.
• B. Handsets require external power to operate.
• C. Handsets cannot be repaired in the field.
• D. Handsets are designed for digital signaling only.

Answer: (A)

Handsets in sound-powered telephone systems are designed to operate without any external power. The signal comes from the user’s own voice, and the circuitry is built to be rugged and simple so it can run reliably across long watches and various shipboard conditions. Because they don’t rely on batteries or external power, they’re well suited for continuous, long-term use in the field and on the shop floor. That’s why the idea that handsets aren’t designed for long-term communication doesn’t fit how these devices are meant to function on a ship.

The other statements don’t fit either: they don’t require external power at all, they can be repaired in the field, and they’re not limited to digital signaling—sound-powered handsets convey analog audio through the line.