NA

∴ 272 = 2 + 7 + 2 = 11
210 = 2 + 1 + 0 = 3
240 = 2 + 4 + 0 = 6
304 = 3 + 0 + 4 =7
The sum of digit of all numbers except 240 is a prime number, whereas sum of digits of the number 240 is a non-prime. Hence, it is different from all others.