Nick is two years old, lives with his mother and father, and incorrectly refers to all men as 'daddy.' Which of the following concepts best explains Nick's error?

Overregularization refers to a language phenomenon where children apply regular grammatical rules to irregular words, such as saying "goed" instead of "went." This concept does not apply to Nick's situation, as his use of 'daddy' does not involve incorrect application of grammatical rules but rather a misapplication of a word's meaning.

Underextension occurs when a child uses a word too narrowly, applying it to fewer objects than it should. For example, if Nick only referred to his father as 'daddy' and not to other fathers, that would demonstrate underextension. This concept does not align with his behavior of using 'daddy' for all men.

Fast mapping is a process where children learn new words rapidly through brief exposure. While this is a critical aspect of language acquisition, it does not explain Nick's broad application of 'daddy' to all men, which is more about misunderstanding than quick learning.

Pragmatics involves understanding the context and social aspects of language use. While it plays a role in overall language development, it does not specifically account for Nick's incorrect labeling of all men as 'daddy,' which is more about vocabulary usage than context.