A recursive rule for a geometric sequence is a1=9; an=2/3(an−1). What is the iterative rule for this sequence?

A.) an = 9 • (2/3)^n
B.) an = 2/3 • 9^n
C.) an = 9 • (2/3)^n-1
D.) an = 2/3 • 9^n-1