Answer: Choice B (middle choice)
Step-by-step explanation:
If you reflected the top triangle over line m, then you'd get what is shown in answer choice C. The two triangles are the same size here, so no dilation has been applied yet. We can rule out choice C for this reason.
After shrinking the bottom triangle, you end up with the diagram in choice B. This is why it's the answer.
Choice A can be ruled out because it appears that your teacher has applied an extra vertical axis reflection to swap the positions of X' and Z'. We should have X' somewhere near and below point X (as choice B indicates). A similar story applies to points Z and Z' as well.