Eric, a salespersons for a technology company, walks into a law firm's office at 8:00 pm. The only person at the office at this time is Arthur is wearing a uniform(blue pants, blue shirt with a name tag " Art") and is picking up trash, cleaning counters, and sweeping. Eric asks Art if the law firm wants to buy a new VOIP telephone system costing 50000 dollar. Art says "yes." Eric then presents a contract for the sale and Art signs it for the law firm. Under these facts it is most likely that:

A. The law firm is not bound unless Art had express

B. The law firm is bound under respondeat superior

C. The law firm is bound based on apparent authority

D. The law firm is bound based on implied authority