The correct response for explaining how the SAS (Side-Angle-Side) criterion can be used to prove similarity in two triangles is:
If two corresponding side lengths of each triangle are given and are proportional, with a proven included angle measure, the triangles are similar.
This means that if two sides of one triangle are in proportion to two sides of another triangle, and the angle formed between those sides is equal in both triangles, then the two triangles are similar.