Find the missing number?

Answer: Option C

The Sequence 2, 4 , 3, 7 , 5, 11, 8, 16, 12, x can be divided into two sub sequence such as
2, 3, 5, 8, 12 and
4, 7, 11, 16 , x.

For First Sequence, 2
2 + 1 = 3
3 + 2 = 5
5 + 3 = 8
8 + 4 = 12.
For Second Sequence, 4
4 +3 = 7
7 + 4 = 11
11 + 5 = 16
16 + 6 = 22.
So, Missing Element = 6.