At the start of "The Necklace," why does Mathilde's husband go through "great trouble" to get an invitation to the ball?

AHe knows that attending the ball will lead to his getting a promotion at work.

BHe has bought Mathilde a new dress and wants her to wear it for some special event.

CHe thinks attending such an elegant affair will make Mathilde happy.

DHe wants to prove to Mathilde that he is very good at his job.