Mark the letter A, B, C, or D to indicate the sentence that best combines each pair of sentences in the following questions.
Enormous efforts have been made. People want to find a cure for this disease.
A. Enormous efforts have been made; however, people want to find a cure for this disease.
B. Enormous efforts have been made, so people want to find a cure for this disease
C. Although enormous efforts have been made, people want to find a cure for this disease.
D. Enormous efforts have been made to find a cure for this disease.