Explanation:

Correct option:3

Solution:

Given: 30a68b (a > b) is divisible by 11

If the difference between the sum of the digits at the odd and even places equal 0 or divisible by 11, the number is divisible by 11.

 (3 +a+ 8)-(0 + 6 +b)= 0

 For a = 9, b = 3 [a>b]

9 - 3 = 6

The greatest value of b is 3, when 30a68b (a > b) is divisible by 11.