Answer:
It's A.
Step-by-step explanation:
B doesn't make sense because you have to rotate the figure to get it on it's side, and there is no rotation involved.
C doesn't make sense because there's a reflection AND a scale factor of 2.
D doesn't make sense because there's a scale factor of 2.
A makes sense because a scale factor of 1/2 halves the size and the rotation lands it in the corresponding place.
