What is the prime factorization of 44?

4 x 11
2 x 22
2 x 2 x 11
2 x 2 x 2 x 5

The prime factorization of 44 is C, 2x2x11 since all of these numbers (2 and 11) are prime numbers. 4 is not prime, so that rules out A, 22 is not prime, so that rules out B, and 2x2x2x5 equals 40, not 44, which rules that out.