Answer:
B. Human toddlers walking
Step-by-step explanation:
A bird feeding its young is innate, their kids need to eat and communicate it to their parents.
A child recoiling from a hot stove is a reactive behavior, they're not going to learn how to lift their hand from the stove, it's hot, they're going to move.
Squirrels opening nuts is also innate, they need food and opening nuts is how they get food.
Therefore the answer is B, human toddlers learn how to walk.