Why are light-years more convenient than miles, kilometers, or astronomical units (au) for measuring the distances to stars and galaxies?

Stars and galaxies are very far from the Earth. If their distance were denoted by km or AU then the numbers would be very large. Light-year makes the representation of distance to be concise.

Explanation:

Stars and galaxies are very far from the Earth. If their distance were denoted by km or AU then the numbers would be very large. Light-year makes the representation of distance to be concise.

The distance light travels in one year is called a light-year.

As it can be seen here that 1 light year = 9.46728×10¹⁵ m expressing distances of stars and galaxies which are more than 1 light-year becomes easier. Converting it to km will make it 9.46728×10¹² km does not make much difference.

1 Astronomical unit (almost the distance between the Earth and Sun) = 149597870700 m is also not enough to represent the distances of stars and galaxies.

the answer is a. at the equator