Swimming alone
a. is acceptable in a pool but never in a lake or an ocean.
b. increases the benefits of swimming for cardiorespiratory endurance.
c. is never safe, regardless of ability.
d. is ok as long as you've been swimming for at least five years.

Which of these is a sexual stereotype? a) on average, males are taller than females. b) people over the age of 60 are not interested in sex. c) male hormone levels differ from those of females. d) there are more male representatives than female representatives in congress.