单选题 It is suggested by the authors of the paper that their subjects are more prone to get heart disease than other groups.

【正确答案】 C

【答案解析】be prone to“易于，倾向于，有可能”。一般说来，B项possible作表语的不多。D项prompt“敏捷的，及时的”；C项likely正好可以作表语，因此为正确选项。