Answer: (a) -6x²y
Explanation:

X to the power of 2 should be cancelled from the top and bottom, which leads to:

Then Y to the power of 1 should be cancelled from top and bottom (since it can go into both), which leads to:

Then find the highest common factor (which is 3), and cancel it out from the top and bottom, which leads to:

which equals to
-6x²y (a)