I'msureheisuptothejob___hewouldgivehismindtoit.[A]ifonly[B]incase[C]until[D]unless翻译整句并对所选答案进行解释

　　I'msureheisuptothejob___hewouldgivehismindtoit.

　　[A]ifonly[B]incase[C]until[D]unless

　　翻译整句并对所选答案进行解释