Answer:
I've seen this question before, and I don't know if you're looking at the multiple choice version. If you are, I believe the answer is d)Fruit flies prefer mates adapted to the same food source.
Explanation:
The four options are these:
A. Fruit flies mate randomly regardless of how they were bred.
B. Fruit flies can adapt to eating different food sources.
C. Fruit flies prefer the container where they were bred.
D. Fruit flies prefer mates adapted to the same food source.