The previous answer from another person got deleted, so I'm here to put it back in my own words.
(Edit: The answer is A)
First of all, you can take 4 out of each, so simplify everything by 4.
4(x^4 - 6x^3 + 9x^2)
Next, you can see that you're able to take out x^2
4x^2(x^2 - 6x + 9)
You can see that both x^2 and 9 are perfect squares, meaning you can crunch them together like this
(x+3)^2 or (x-3)^2
Of course, only one would work, and as fate has it, (x-3)^ produces x^2 - 6x + 9
This would turn the now factored equation into :
4x^2(x-3)^2 or 4x^2(x-3)(x-3), this means the answer is A