Donna, Authorized Her Friend Joyce to Sell His Prada Bag

Donna, authorized her friend Joyce to sell his Prada bag worth ₱100,000 on installment basis. Joyce, however, sold the bag on cash in contravention of the authority given to her. Was the sale valid?

A) No, because the agent acted beyond the scope of his authority.
B) Yes, because the sale in cash redounds to the benefit of Donna. Hence, despite violation of the authority given, the sale is valid.
C) Yes, because Donna as principal is always bound by the act of his agent, Joyce.
D) No, because the agent violated the terms of the authority given to her.