To find the coordinates of Point Q after reflecting Point P (-3, 3) across the x-axis, you need to change the sign of the y-coordinate while keeping the x-coordinate the same.
Thus, the y-coordinate of P (which is 3) becomes -3 after reflection, while the x-coordinate remains -3.
Therefore, the coordinates of Point Q are (-3, -3).
The correct answer is: A. (-3, -3)