Difficult though the exam was, he still passed it...

Câu hỏi: Difficult though the exam was, he still passed it with flying colours. 

A. Because the exam was difficult, he passed it with flying colours.

B. Although the exam was difficult, but he still passed it with flying colours.

C. No matter how difficult the exam was, he still passed it with flying colours.

D. The exam was not too difficult, so he could pass it with flying colours.