【单选题】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
【单选题】In Paragraph One, the sentence 'Experts long have been concerned about such growth', the phrase 'concerned about' is similar in meaning to________.