Answer:
C: She wishes to calm Mary and cover up her own lack of composure.
Explanation:
Jane Austen's "Persuasion" revolves around the life of a young woman named Anne Elliot and her struggles with family, love, and friendship. The novel deals with the common themes of social status, class rigidity, marriage, and one's profession as deemed 'fit' in a society.
In the given passage from the text, Mary revealed she saw Mr. Elliot and Mrs. Clay together which Anne denied for Mr. Elliot "was to leave Bath at nine this morning, and does not come back till to-morrow." But when Mary insisted it was them, Anne had no choice but to go and see for herself. She did it mainly to calm Mary and also to hide her embarrassment in not knowing what is really going on or who Mr. Elliot really is.
Thus, the correct answer is option C.