On Average, Middle-Aged People Tend to Have Higher Incomes Than

On average, middle-aged people tend to have higher incomes than younger or older people do because:

A) they receive more money from the government than the younger or older people do.
B) they are at an age where their productivity is at its peak.
C) they participate in the labor force to a lesser extent than do the young or the old.
D) they are subject to lower rates of taxation than the younger or older workers.
E) they have more number of dependents to look after than the younger and older people.