Which of the following numbers is divisible by 56?
56 = 8x7 = 2x2x2x7
Since 3 of the choices end with 8, let's assume one of them is correct. Start by dividing C, D, E by 7 to see if they will be able to show a partial prime factorization of 2x2x2x7.
(c) does not
(d) 7 divides into 289968 41,424 times. Does 41,424 divide by [2x2x2], or 8? Yes, so (d) is correct.