The correct option is C 6
A number is divisible by 18 when it is divisible by both 2 and 9
For divisible by 2 unit digit of number be 2,4 ,6 8
For divisible by 9 sum of all digit should be divisible by 9.
In d456d d is 6 because 6+4+5+6+6=27
Sum of all digit is divisible by 9 and unit digit is also divisible by 2
so the number is divisible by 18 is64566