One number has a prime factorization of 2 3 • 3 2, and another number has a prime factorization of 2 2 • 3 3. Which of the following expressions would equal the greatest common factor of these two numbers?
2 5 • 3 5
2 3 • 3 3
2 2 • 3 2
2 • 3
2 5 • 3 5
2 3 • 3 3
2 2 • 3 2
2 • 3