What is the primary difference between a Class M1 and a Class M2 license in California?

1. An M1 license is for riders over 21, while an M2 is for riders under 21.
2. An M1 license has nighttime restrictions, while an M2 does not.
3. An M1 license allows operation of any motorcycle, while an M2 is for mopeds and motorized bicycles.
4. An M1 license requires passing a skills test, while an M2 only requires a written test.