A boy's first ejaculation usually does not contains fertile sperm

Why is the median age (the age at which half the population is older and half is younger) rising in the developed world?

A) The baby boom generation is dying off. B) Fertility is declining and the baby boomers have entered later life. C) Birth rates are going up. D) Life expectancy is decreasing.

The dependent variable in this study was

(a) the set of players (b) whether the subjects selected or were assigned players (c) how much money the subjects wanted for their player names (d) the correlation between the two groups of participants (e) none of the above