If ABC is similar to DEF, the sides of ABC must be congruent to the corresponding sides of DEF.

Answer:
Option B. False
Step-by-step explanation:
If triangle ABC is similar to DEF then for the similarity of these triangles all angles should be similar or same.
In addition to the angles their corresponding sides should be in the same ratio, in other words sides should be dilated by a scale factor.
Therefore the given statement is false.
Option B. False is the answer.