The teacher has done his best to help all students...

Câu hỏi: The teacher has done his best to help all students. However, none of them made any effort on their part

A The teacher has done his best to help all student, then, none of them made any effort on their part

B Although the teacher has done his best to help all students, none of them made any effort on their part

C Because the teacher has done his best to help all students, , none of them made any effort on their part

D If the teacher has done his best to help all students, , none of them made any effort on their part