which choice is the
explicit formula for the following geometric sequence?

0.3,-0.06, 0.012,-0.0024, 0.

a. a = -0.2(0.3)^(n-1)
b. ap=0.3(0.2)
c. an = 0.3(-0.2)^(n-1)
d. an = -0.3(-0.2)^(n-1)
e. a = -0.3(0.2)^(n-1)