下列哪一种情况下心脏的排血量增加（）

A.动脉瓣狭窄

B.维生素B缺乏

C.动静脉瘘

D.房间隔缺损

E.粘液性水肿

—Is this your violin?

—No. Ask Mary. It must be ________. She's the only one who plays the violin in our class.[ ]

A. mine

B. his

C. hers

D. ours