is this pencil为什么不对

Question

-Is this a pencil?-_________.A.Yes,thi
-Is this a pencil?
-_________.
A.Yes,this is.
B.Yes,they are.
C.No,it isn't.

Answer 1

选择C,is提问,不能用are 来回答,所以B不对.Is this 提问,一般是Yes,it is 或者No,it isn't.来回答