Depth of ocean is measured by A. Animometer B. Aerometer C. Siesmometer D. Fathometer

The correct answer is D. Fathometer.

A fathometer is an instrument used to measure the depth of water. It is typically used on ships and boats to determine the depth of the water below the keel. Fathometers work by emitting a sound wave that travels through the water and is reflected back by the bottom. The time it takes for the sound wave to travel and return is used to calculate the depth of the water.

Animometers, aerometers, and seismographs are all instruments that measure different things. An anemometer measures wind speed, an aerometer measures air density, and a seismograph measures earthquakes.

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