Question

____ equipment sends out ultrasonic waves, striking a hidden object, reflecting off of it, and returning to the source.

answer options:
select one of four

radio
oscilloscope

sonar
stethoscope

Explanation:

Radio uses electromagnetic waves for communication, not ultrasonic waves. Oscilloscope is for measuring electrical signals. Stethoscope is for medical auscultation. Sonar (Sound Navigation and Ranging) uses ultrasonic waves to detect objects by sending waves, having them reflect off objects, and return to the source.

Answer:

C. Sonar