A rational person does not act unless

a$.$ the action makes money for the person.

b$.$ the action is ethical.

c$.$ the action produces marginal costs that exceed marginal benefits.

d$.$ the action produces marginal benefits that exceed marginal costs.

e$.$ None of the above is true.

Suppose you find $$20.$ If you choose to use the $$20$ to go to the football game, your opportunity cost of going to the game is

a$.$ nothing because you found the money.

$($b$)$ $$20($because you could have used the $$20$ to buy other things$).$

c$.$ $$20($because you could have used the $$20$ to buy other things$)$ plus the value of your time spent at the game.

d$.$ none of the above.

Raising taxes and increasing welfare payments