People who often stay up too late are more likely to die of

People who often stay up too late are more likely to die of heart disease.
People who often stay up too late are more likely to die of heart disease,______a stady.
A.with the help
B.because of
C.according to
D.as a result
选哪个啊.还有这句话怎么翻译?likely是什么意思.