Altruism Involves ____, but Reciprocal Altruism Involves ____

Altruism involves ____, but reciprocal altruism involves ____.

A) the sacrifice of an individual's reproductive success to help others; the expectation of a future favor in return for present aid
B) aid given to nonrelatives; benefits given to close relatives only
C) the expectation of a future favor in return for present aid; close relatives helping each other
D) low-risk behavior that provides minor benefits to others; high-risk behavior providing major benefits to others
E) aid given to relatives; benefits given to nonrelatives only