Answer:
B
Step-by-step explanation:
Reflection is a transformation that preserves lengths.
Triangle XYZ, with side lengths XY = 7 in, YZ = 5 in, XZ = 4 in, is reflected across the x-axis to result in △X'Y'Z'.
This means that corresponding sides have the same lengths:
- XY = X'Y' = 7 in;
- XZ = X'Z' = 4 in;
- YZ = Y'Z' = 5 in.
Find the perimeters of both triangles:

Hence, only option B is true.