Find the missing number?

A. 1

B. 9

C. 11

D. 7

Answer: Option A

Solution(By Examveda Team)

Logic ( Top to Bottom):
Sum in the row increase by 5.

5
7 + 3 = 10
5 + 8 + 2 = 15.
So,

9 + 6 + 4 + 1 = 20
x = 1.