meters per second (m/s) light-year (ly) astronomical unit (AU) electromagnetic unit (EMU)
I am hesitating between 4 options to answer the following question, which option should I choose?
Question: The distance from Earth to the Sun is about 150,000,000 km. What abbreviation do scientists use to describe this distance?
Possibilities:
- meters per second (m/s)
- light-year (ly)
- astronomical unit (AU)
- electromagnetic unit (EMU)

astronomical unit (AU)