Mason is 17 years old, a junior in high school, and lives with his parents. He had unearned income of $750. Can his parents claim him as a dependent? Does he have to file a tax return?

a: Mason can be claimed as a dependent by his parents and he is not legally required to file a tax return
b: Mason can not be claimed as a dependent by his parents and he is not legally required to file a tax return
c: Mason can not be claimed as a dependent by his parents and he is legally required to file a tax return
d: Mason can be claimed as a dependent by his parents and he is legally required to file a tax return