Nautical mile is a unit of distance used in: A. Navigation B. Road mile C. Astronomy D. Measuring the boundaries of a nation

The correct answer is: A. Navigation

A nautical mile is a unit of distance used in navigation. It is equal to one minute of arc along a great circle of the Earth, which is approximately 1.852 kilometers (1.150778 miles). Nautical miles are used to measure distances at sea and in the air.

Road miles are a unit of distance used on roads. They are equal to 1.609344 kilometers (0.994677 miles). Road miles are used to measure distances on roads and highways.

Astronomy is the study of objects and phenomena in outer space. It is not a unit of distance.

Measuring the boundaries of a nation is not a unit of distance.