The following questions present a sentence, part of which or all of which is underlined. Beneath the sentence, you will find five ways of phrasing the underlined part. The first of these repeats the original; the other four are different. If you think the original is best, choose the first answer; otherwise choose one of the others.
These questions test correctness and effectiveness of expression. In choosing your answer, follow the requirements of standard written English; that is, pay attention to grammar, choice of words, and sentence construction. Choose the answer that produces the most effective sentence; this answer should be clear and exact, without awkwardness, ambiguity, redundancy, or grammatical error.
Medical experts have amassed evidence concluding that users of smokeless tobacco be more prone to heart disease, hypertension, and mouth cancers than people who do not use smokeless tobacco.（）
A. be more prone to heart disease, hypertension, and mouth cancers
B. are proner to heart disease, hypertension, and mouth cancers
C. are more prone to heart disease, hypertension, and mouth cancers
D. experience heart disease, hypertension, and mouth cancers at heightened rates
E. suffer heart disease, hypertension, and mouth cancers at a higher risk
