B and C are absurd; if a series converges, it must have a sum, but if a series diverges, it cannot have a sum.
Now, notice that

That is, we can write the sum more compactly as

The series is geometric with common ratio

, so the series converges (and thereby has a sum), so the answer is D.
Answer:
2
Step-by-step explanation:
2jklejlkwmf,wne/lkrnhwk4orjlenbkjbrkjb23kjrb23kjrb
3 and what?
if it is 3 and 5 than the answer would be 15