Question

一 Hi, Jim! Is this your bike or Mary's?
— It's mine, not        

1. A.
   her
2. B.
   him
3. C.
   his
4. D.
   hers

Answer 1

D
名词性物主代词。答句意为“是我的，不是她的”，此处用名女性的名词性物主代词，因此选D。