Hey there! :D
The best answer is: "D"
A number that is divisible by 9 is also divisible by 3 because 3 is a factor of 9.
All of the numbers divisible by 9 are also divisible by 3, so "B" and "C" can be ruled out. Not all of the factors of 9 are factors of 3. 9 is a factor of 9. 9 is NOT a factor of 3.
I hope this helps!
~kaikers
