Answer: The correct answer is B.
Explanation:
In the given problem, Sonar signals and infrared light are are used to send messages to submarines deep under water.
Infrared light is a electromagnetic wave. It travels with the speed of light.
Sonar wave travels at the speed of the sound in water. Sound is a mechanical wave. The speed of the electromagnetic wave is faster than the mechanical wave. Therefore, the infrared light gets there faster and is clearer.
Therefore, the correct answer is B.