新概念3 LESSON11 mutiple choice question comprehention

新概念3 LESSON11 mutiple choice question comprehention
第2题为什么不选D
what made the Customs Officer's face light up?
A ,Knowing how difficult it would be for the writter to close his case
B,Seeing the bottle of hair gel which he could charge duty on
C,the idea of having found something which should have been declared
D,Discovering an unopened bottle of perfume at the bottom of the case