Answer: B. Overextension.
Explanation: Overextension is when we use a word to refer to a group of similar things, it is very common in children because they don't have a extensive vocabulary. An example of overextension is when children use the word "doggie" to refer to every four-legged animal they see, this is because they think that "doggie" is a term for animals with four legs, and not only for dogs.
