Several studies have found that the coronary patients who exercise most actively _____.
选项：

A:are at least fifty percent less likely than those who are sedentary to die of a heart attack
B:have half the chance, or less, of dying of a heart attack than those who are sedentary do
C:have half the chance that they will die of a heart attack, or less, than those who are sedentary do
D:are at least fifty percent less likely to die of a heart attack as those who are sedentary