Mark the letter A, B, C, or D on your answer sheet...

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.

1 find it very challenging. It requires a lot of concentration and determination.

A. I find it very challenging, for it requires a lot of concentration and determination.

B. I find it very challenging, so it requires a lot of concentration and determination.

C. I find it very challenging, yet it requires a lot of concentration and determination.

D. I find it very challenging, though it requires a lot of concentration and determination.