Which of the following persons could be rated as a preferred risk?
a. a physically fit non-smoker with a non hazardous job whose hobby is sky diving.
b. a person who exercises regularly, does not smoke, has no dangerous hobbies, and whose occupation is roofing high-rise buildings
c. a non-smoking office worker who is considerably overweight
d. a secretary who jogs three times a week , does not smoke and is physically fit.