Which of these phrases is correct?
A 9 is a multiple of 3 and a factor of 12.
B 9 is a factor of 45 and a multiple of 5.
C 9 is a multiple of 6 and a factor of 72.
D 9 is a factor of 54 and a multiple of 3.
A is wrong. 9 is not a factor of 12.
D. is correct.