Why is AB congruent to DE?
A. If two legs of one right triangle are congruent to the corresponding legs of another right triangle, then the two triangles are congruent.
B. If two triangles are congruent, then the corresponding parts of the congruent triangles are congruent. (CPCTC)
C. Parallel lines cut by a transversal are congruent.
D. If three sides of one triangle are congruent to three sides of another triangle, then the two triangles are congruent.