Economists have frequently hypothesized that industrialization and its correlates played a major role in inducing fertility decline in the United States after 1850. ... This leaves changes in the cost of raising children as the likely driver of the industrialization result.
The correct answer is A. Pay interest on savings accounts.
They use your money to give out loans and when people pay the loan back with interest, they take the interest and split it between themselves and your account because you were helpful to them.
In resource markets, individuals buy factors of production.