根据规定，下列各项中，属于混同原因的有( )。

A．债权人下落不明

B．双方互存债权和债务

C．所有权与他物权归属一人

D．主债务与保证债务归属一人

E．债权与债务归属一人

_____, I managed to get through the game and the pain was worth it in the end. [ ]

A. Hopefully

B. Normally

C. Thankfully

D. Conveniently