What is an astronomical unit or AU?

A)

A unit of time equal to one light year or 6 trillion miles.

B)

A unit of distance equal to the average distance from Earth to the Suntor

93 million miles.

A unit of distance equal to the size of the Milky Way Galaxy or 100,000

light years across

D)

A unit of time that is equal to the amount of time it takes light to travel

from the Sun to Earth,