First we need to find the common ratio of the sequence. We do this by dividing each number by the previous number to it:



So the common ratio "r" is 8:

Now we can use the formula to find the nth term of a sequence:

Where "an" is the nth term, "a1" is the first term which in this sequence is 1/8, and "r" is the common ratio which is 8. Substituting this we get the expression that can be used to find the nth term in the sequencehe sequenc:

Thus, the answer is option A: 1/8(8)^n-1