Find an Explicit Rule for the Nth Term of the Sequence

Multiple Choice

Find an explicit rule for the nth term of the sequence.
- $$3 , - 12,48 , - 192 , \ldots$$

A) $a _ { n } = 3 \cdot 4 ^ { n + 1 }$
B) $a _ { n } = 3 \cdot ( - 4 ) ^ { n - 1 }$
C) $a _ { n } = 3 \cdot ( - 4 ) ^ { n }$
D) $a _ { n } = 3 \cdot 4 ^ { n - 1 }$