Find the common ratio for the sequence a, negative a^2/2, a^3/4, negative a to the power of 4 over 6, etc . (5 points)

Please help and explain

A) negative a over 2
B) a/2
C) a
D) The sequence is not geometric, therefore there is no common ratio.

so just divide a_2/a_1 = (-a^2/2) / a

I guess you could check by dividing a_3/a_2, but unless you suspect trickery, one case will do.