Glenn has remarkable stamina for a man in his 70s. He will do a 10-mile bike ride in the morning and then mow the lawn in the afternoon. He claims that his good health is from taking vitamin E every day.
What benefit is offered by Glenn's vitamin intake that seems to limit his aging process?

a. reduction of cross-linking proteins
b. protection from free-radical damage
c. stimulation of telomerase production
d. stabilization of testosterone levels