difficult and challenging the task may be we must finish it on time because there is a

问题补充：

difficult and challenging the task may be, we must finish it on time, because there is a possibility we’ll be fired if we can’t fulfill the task on time．

A. Whatever; that

B. However; that

C. Whatever; which

D. However; as

答案：

A. Whatever; that

(答案→)B. However; that

C. Whatever; which

D. However; as

解析：考查Whatever和 However的用法和从句，However后跟形容词或副词；Whatever后跟名词。That引导的同位语从句，所以选B