Determine Whether the Sequence Is Arithmetic $n$ Begins with 1 $a _ { n } = - 6 + 4 n$

Multiple Choice

Determine whether the sequence is arithmetic. If so, find the common difference. (Assume that $n$ begins with 1.)
$a _ { n } = - 6 + 4 n$

A) $- 4$
B) 6
C) $- 6$
D) 4
E) not arithmetic