Final answer:
Miss Bingley criticizes Elizabeth's social status and family to diminish her in Mr. Darcy's eyes and flatters Mr. Darcy by complimenting his intelligence and discernment.
Step-by-step explanation:
In Jane Austen's novel, Pride and Prejudice, Miss Bingley attempts to diminish Mr. Darcy's opinion of Elizabeth by criticizing Elizabeth's social status and family, which corresponds to option B. To flatter Mr. Darcy, she often compliments his intelligence and discernment, as suggested in option C. This behavior is indicative of Miss Bingley's strategic maneuvering to gain favor with Mr. Darcy, while looking down upon Elizabeth, whom she sees as a rival for Mr. Darcy's attentions.