Angles A and D would have to be congruent in order to prove SAS Similarity Theorem.
“The SAS Similarity Theorem states that if two sides in one triangle are proportional to two sides in another triangle and the included angle in both are congruent, then the two triangles are similar.” (Source: cK-12)
This graphic may help you understand my choice of answer. It shows SAS Similarity Theorem in an alternate example.
