The answer is C, 9. Explanation: the numbers need to be consecutive, meaning they’re next to each other in integer order (the order which goes 1, 2, 3, 4, 5... and so on). Try adding two consecutive numbers from the options you were provided, and the only ones that can equal 17 are 9 added to 8. 8 + 9 = 17. The largest of these two numbers is 9, so the answer is C.
