Which bills aren’t required endorsement when transferred in the following items？下列哪些票据在转让时不需要背书？（）

• A、A Bill of Exchange is payable to Mary or bearer
• B、A Bill of Exchange is payable to bearer
• C、A Bill of Exchange is payable to Mary
• D、A Bill of Exchange is payable to Mary only
• E、A Bill of Exchange is payable to the order of Mary