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.
The 12th-grade students are studying very hard.. They want to pass the entrance exam.
A. The 12th -grade students are studying very hard so as pass the entrance exam.
B. The 12th -grade students are studying very hard in order that to pass the entrance exam.
C. The 12th -grade students are studying very hard so to pass the entrance exam.
D. The 12th -grade students are studying very hard so that they can pass the entrance exam.