A firm has two partners: Jim and Bill. Jim owns 60% of the partnership and Bill owns 40%. In which of the following transactions will the partnership be held responsible for an individual partners' actions?

A. Jim buys a laptop on credit for personal use.

B. Bill defaults on payment of his personal credit card bill.

C. Jim signs a contract as a guarantor for Bill's personal loan.

D. Bill signs a contract to buy furniture for official use in the partnership.