the time of year it was born the type of food the bird eats the bird's migratory patterns what the bird inherited from its parents
I gave my students this multiple choice question: Birds come in a variety of colors, shapes, and sizes. Which usually determines the color, shape, and size of a bird?

Only one answer is correct among these 4 choices:
- the time of year it was born
- the type of food the bird eats
- the bird's migratory patterns
- what the bird inherited from its parents

Could you tell me which one is correct?

what the bird inherited from its parents