Answer:
A
Step-by-step explanation:
∆ABC is similar to ∆DEF if and only if the ratio of their corresponding side lengths are the same.
Let's find out:
DE/AB = 10/5 = 2
EF/BC = 8/4 = 2
FD/CA = 12/6 = 2
The ratio of their corresponding side lengths are equal, therefore, ∆ABC is similar to ∆DEF based on the SSS Similarity Theorem.
