Find the missing number?

Answer: Option C

Starting with the top left segment, and moving clockwise around the circle, numbers follow the sequence of square numbers, from 121 to 256.

11* 11 = 121.
12 * 12 = 144.
13 * 13 = 169.
14 * 14 = 196.
15 * 15 = 225.
16 * 16 = 256.
Missing Element = 196.