Answer : 4. "6"
Explanation :

Answer: D) 6 Explanation: Sum of numbers in the outer circle in before Arc should come in inner circle patterns in the clock wise direction next Arc. i.e, 9+6 = 15 comes in next arc of inner circle 7+3 = 10 comes in next arc of inner circle In the same way, 4+2 = 6 comes in place of '?'.