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.
These chemicals are very toxic. Protective clothing must be worn at all times.
A. Since these chemicals are very toxic, so protective clothing must be worn at all times.
B. So toxic are these chemicals that protective clothing must be worn at all times.
C. These chemicals are such toxic that protective clothing must be worn at all times.
D. These chemicals are too toxic to wear protective clothing at all times.