What is the explicit rule for this geometric sequence? 4,4/5,4/25,4/125, ...

a) an=15⋅4n

b) an=4⋅ (15) n

c) an=15⋅4n-1

d) an=4⋅ (15) n-1

So for the formula of geometric sequence is:

An = ar^ (n-1)

Where an is the nth number

a is the first term

r is the common ratio

n is the number of terms

since a = 4

r = (4/5) / 4 = 1/5

an = 4 (1/5) ^ (n-1)

if the syntax of the choices are correct the answer maybe D