Number 1 is the main idea. It covers what the rest are giving examples of. It is not one specific example but rather an idea.
The two jobs when reading the exposition are to learn the setting and who the main characters are.
After Bounderby marries Louisa, Mrs. Sparsit makes it her mission to undermine and destroy the marriage and to catch Louisa in the act of adultery. At the same time, Mrs. Sparsit is one of the more comic characters, useful for lightening the mood every now and again in this bleak novel.
Enumeration<span> is used for listing the details or a process of mentioning words step by step
It means a list</span>