The answer is D.
Since the two triangles are congruent, they would have equal angles.
The reason why the other answer choices are wrong...
A) ∠S is equal to ∠Y, not ∠Z.
The angle that is equal to ∠Z is ∠T.
B) Line ST is equal to Line YZ, not Line XZ.
The Line that is equal to Line XZ is Line RT.
C) Line RS is equal to Line XY, not Line ST.
The Line that is equal to Line ST is Line YZ.
Hope this helped! Brainliest is always welcome :)