Since each term is a multiple of the previous term, this is a geometric sequence, because there is a common ratio. (The constant found when dividing any term by the previous term.) Any geometric sequence can be expressed as:
a(n)=ar^(n-1), where a=initial term, r=common ratio, n=term number:
We are told that a=1 and r=3 so
a(n)=3^(n-1), so the 200th term is:
a(200)=3^199
So your answer is C.