Which of These Smokers Exhibits an Optimistic Bias

Which of these smokers exhibits an optimistic bias?

A) Jim overestimates the danger of smoking and believes that he has a very high chance of developing a smoking-related disease before age 60.
B) Loraine believes that smoking is not really dangerous and so she has about the same risk for smoking-related diseases as do other people.
C) Robbie overestimates the danger of smoking and believes that she has about the same risk for smoking-related diseases as do other people.
D) Joe understands the danger of smoking but believes that his risk of a smoking-related disease is less than that of other smokers.