If the fifth term in a geometric sequence is 1∕27 and the common ratio is 1∕3, find the explicit formula of the sequence.
Question 18 options:

A)

an = (1∕3)n – 1 for n ≥ 1

B)

an = (1∕27) ⋅ (1∕3)n – 1 for n ≥ 1

C)

an = (3) ⋅ (1∕3)n – 1 for n ≥ 1

D)

an = (3) ⋅ (3)n – 1 for n ≥ 1