Determine if the following claims are true or false. Justify each answer you give with at most three sentences.

a. Facemasks produced by the public sector are an example of a public good.

b. The consumer price index includes the prices of imported goods.

c. When the marginal propensity to consume increases, the aggregate demand function becomes steeper.

d. The economic burden of an increase in the land tax is borne by rental households.

e. A tax is regressive whenever the monetary amount of the tax decreases with income.

f. You refusing to take the flu shot exerts positive externalities to other people.