A coded alarm signal consists of how many complete rounds of the number transmitted?

• A. Three or more
• B. Two
• C. One
• D. Four

Answer: (A)

The signal uses repetition to ensure reliability and proper recognition. A coded alarm is transmitted in complete cycles, and the minimum standard is to have at least three full rounds of the number so the receiver can confidently distinguish the code from noise or a brief glitch. One round could be mistaken for a transient beep, and two rounds might still be ambiguous under imperfect conditions. Repeating three or more times provides enough redundancy for accurate decoding, which is why this option is the best answer. Four rounds or more would also satisfy the requirement, but the key point is the minimum of three.