Questions: In "Binding Memories," a book's spine serves as an extended metaphor for the speaker's support for her sister's marriage. determination to reach her goals. interest in many different subjects. deep enthusiasm for reading.

The answer is the speaker's support for her sister's marriage.

In "Binding Memories," the metaphor of a book's spine is used to symbolize the support and strength that the speaker provides for her sister's marriage. Just as a spine holds a book together, the speaker's support is crucial in holding the marriage together and providing stability.

While determination is a strong and important trait, it does not align with the metaphor of a book's spine in the context of "Binding Memories." The spine metaphor is more about support and structure rather than personal ambition.

An interest in various subjects would be more appropriately symbolized by the content within the pages of a book rather than the spine. The spine represents something that holds and supports, not the diversity of interests.

Enthusiasm for reading would again be more related to the content of the book rather than the spine. The spine's role is to provide support and structure, which aligns more closely with the idea of supporting a marriage.