Answer:
D
Explanation:
A robin building a nest is not learned or taught like the others. It is just instinctive for robins to build nests.
You’re answer is C. I hope this helps!
Both parents must be carriers, which means they have the heterozygous gene (one uppercase letter & one lower case letter). They will still carry that mutated gene (because they have a lower case letter), and their offspring will have a 25% chance of getting a recessive disorder. The percentage is low but still possible.