Find the missing number?

A. 8

B. 5

C. 7

D. 6

Answer: Option B

Solution(By Examveda Team)

Take pairs of numbers at opposite ends of the diagram. Their total is always 10. i.e
Firs Element + last Element = 10
Second Element + second Element from last = 10
So,

5 + x = 10
x = 5.