Answer:
A). An introduction to the members of the Lin family.
Step-by-step explanation:
'An introduction to the members of the Lin family' is the element of the plot that is revealed through the given excerpt. The details like 'family of four' suggest that there are four members in the Lin family including the narrator, his younger brother, and their parents. This introductory or expository part of the plot primarily functions to introduce and familiarize the characters of the Lin family to the audience. It also assists in providing necessary background information and establishing the key idea of the text that it is going to deal with. Thus, option A is the correct answer.