light-year, astronomical unit, kilometer, angstrom angstrom, kilometer, astronomical unit, light-year astronomical unit, angstrom, kilometer, light-year kilometer, angstrom, light-year, astronomical unit
I am hesitating between 4 options to answer the following question, which option should I choose?
Question: Which of the following lists units of length from smallest to largest?
Possibilities:
- light-year, astronomical unit, kilometer, angstrom
- angstrom, kilometer, astronomical unit, light-year
- astronomical unit, angstrom, kilometer, light-year
- kilometer, angstrom, light-year, astronomical unit

angstrom, kilometer, astronomical unit, light-year