Answer: The correct answer is Option b. Distance.
Explanation:
Scientists and astronomers use this unit to measure the distance in space. A light year is a unit of distance and not time because light travels very fast and it travels a lot of distance in one year.
Light year is basically defined as how far the beam of light travels in a year.
Therefore, this light year is a unit of distance. Hence, the correct option is option b.
[tex]1\text{ light year}=5.879\times 10^{12}miles[/tex]
