A light year' is a unit that is used to measure:

Correct option is C

The correct answer is (c) distance.
· A light year is a unit of distance used in astronomy to measure the vast distances between celestial objects.
· It is defined as the distance that light travels in one year in a vacuum, which is approximately 5.88 trillion miles or 9.46 trillion kilometers.
· Light travels at a speed of about 299,792 kilometers per second (186,282 miles per second), and over the course of a year, this distance adds up to a light year.
Information Booster:
· Time: A light year is not a measure of time. Time is measured in seconds, minutes, hours, etc.
· Motion: A light year does not measure motion. Motion is described in terms of velocity or speed.
· Speed: A light year does not measure speed. Speed is the rate at which an object moves and is measured in units such as meters per second or miles per hour.