Does J have a great number of different primes than K?
Statement 1= different prime numbers are 2, 3 and 5. ; this statement is insufficient as it needs to be compared to the number of prime factor of K

Statement 2=The only different prime factors are 5 and 2 ; This statement is insufficient alone because we have to know how many factors J has

Statement 1 and 2 together
K has 3 factors and J has factors 2 factors. Hence, the two statements together is sufficient so answer = Option C because both statement together are sufficient but neither statement alone is sufficient