Prime numbers are those which have factors as one and the number itself.

List of prime numbers is 2, 3, 5, 7, 11, 13, 17, 19, 21, 23 ……

Divisors of 60 are 1, 2, 3, 4, 5, 6 10, 12, 15, 20, 30, 60

So 1 × 60 = 60

2 × 30 = 60

3 × 20 = 60

4 × 15 =60

5 × 12 = 60

6 × 10 = 60

The elements of the set are prime numbers which are divisor of 60 that is 2, 3 and 5

The roaster form of set is

D = {2,3, 5}