Answer: Option B
:
B
Explanation:
Option (a) is incorrect: Pitometer logs (also known as pit logs) are devices used to measure a ship's speed relative to the water.
Option (b) is correct: An odometer or odograph is an instrument used for measuring the distance traveled by a vehicle, such as a bicycle or car. The device may be electronic, mechanical, or a combination of the two (electromechanical).
Option (c) is incorrect: An opisometer, also called a curvimeter, meilograph, or map measurer, is an instrument for measuring the lengths of arbitrary curved lines.
Option (d) is incorrect: Sonar is a device for finding objects underwater using sound waves. Sonars transmit ultrasonic waves into the water below and receive the returning echoes from the seabed.