Find the First Four Terms of the Given Sequence $$a _ { 1 } = 9 , a _ { n } = a _ { n } - 1 + 3$$

Multiple Choice

Find the first four terms of the given sequence.
- $$a _ { 1 } = 9 , a _ { n } = a _ { n } - 1 + 3$$

A) $0,3,6,9$
B) $9,3,6,9$
C) $9,12,15,18$
D) $12,15,18,21$