The two shapes that show an enlarrgement of X by a factor -1 are A and C.
Which shapes are an enlargement by a factor of -1?
We can have either a vertical or an horizontal enlargement, the vertical one is written as:
g(x) = -f(x) ---> This is a reflection over the horizontal axis.
The horizontal one is:
g(x) = f(-x) ---> This is a reflection over the vertical axis.
So we just need to identify the two figures that show a reflection, these are:
A (reflection over the vertical axis)
C (reflection over the horizontal axis)