Answer:
If an animal is a bird, then it can fly.
Explanation:
The other answers don't make sense. Just look for the odd one out, the one that does make sense.
If an animal can fly, then it is a bird: There are animals that are not birds that can fly.
If an animal can't fly, then it is a bird: Birds can fly.
If an animal is not a bird, then it can fly: Not all non-bird animals can fly.