Option 4 : 7

According to the given information-

Adding the digits of **column 1 and 2 we get the number of column 3.**

In column 2 = 3 + 8 + 4 + 4 + 2 + 3 → 24 → (reverse order) → 42 → (42)^{2} → 1764 → 1 + 7 + 6 + 4 → 18

In column 3 = 9 + 3 + 2 + 8 + 2 + 1 → 25 → (reverse order) → 52 → (52)^{2} → 2704 → 2 + 7 + 0 + 4 → 13

**In the same way-**

In column 1 = 1 + 2 + 1 + 2 + 9 + 8 → 23 → (reverse order) → 32 → (32)^{2} → 1024 → 1 + 0 + 2 + 4 → 7

Hence, the correct answer is 7.