If a number is divisible by 6, then it must also be divisible by 2 and 3. So, y must be 0, 2, 4, 6 or 8, but y - x = 1. So, y must be greater than 0 and 2. Now, y can be 4, 6 or 8. If y = 4 then x = 3. If y = 6 then x = 5. If y = 8 then x = 7. Now, the sum of digits of the number must also be divisible by 3. From the option, only y = 4 and x = 3 is divisible by 6. So, this is the correct pair.