Which of these is a geometric sequence?

A. 1/3,2,3,4, ...

B. 2,4,6,8,10, ...

C. 3,15,75,375,1875 ...

D. 2,3,5,9,17, ...

i think the answer to this is c

It's C.

Step-by-step explanation:

A geometric sequence has a common ratio (r) where each term after the first is obtained by multiplying the previous one by r.

Checking through the list we see it is C because:

Second term 15 = first term * 5 = 3 (5) = 15.

Third term = 15*5 = 75,

4th term = 75*5 = 375 and so on.

The common ratio is 5.