Which of the Following Statementsis an Example of an Overextension

Which of the following statementsis an example of an overextension?

A) Julia uses the word "cup" for any container that holds liquid, including vases and birdbaths.
B) Elizabeth substitutes easier sounds for ones that are hard to say, such as "tuck" for "stuck."
C) Eddie expresses his desire for his parents to read to him by using a single word, "book."
D) Robbie leaves out difficult parts of words, as when he uses "tend" for the word "pretend."