Since Income Depends on the Price of the Productive Services

Since income depends on the price of the productive services a person has to sell multiplied by the quantity of those services sold:

A) an increase in the marginal productivity of a service can increase income by making the service more desirable.
B) a decrease in the marginal productivity of a service can increase income by making the service rarer and more desirable.
C) the price of other productive services is irrelevant in determining one person's income.
D) changes in the productivity of other services have no significant influence on the income of owners of still another.
E) none of the above.