Mark the letter A, B, C or D on...

Câu hỏi: Mark the letter A, B, C or D on your answer sheet to indicate the sentence that best combines each pair of sentences in the following questions.

A. Even if they improve the quality of their products, we will order more handbags from them. 

B. Unless they improve the quality of their products, we will order more handbags from them. 

C. Only when they improve the quality of their products will we order more handbags from them. 

D. In case they improve the quality of their products, we will order more handbags from them.