1,2,4,7,_,16
Options:
(A) 11
(B) 9
(C) 10
(D) 12
(E) 13 Let's think first. Stream of consciousness:

Show your work and conclude with the exact phrasing "Therefore, the final answer is [answer]." where [answer] is just the final number or expression that solves the problem.
user
Each new number is the same as the last number with the adder growing by 1. This would yield 11.
So, the answer is (A).