To be effective, an item used as money should serve several functions. Select the statement that best describes money's function as a standard of deferred payment. a. That a currency can be used to express the value goods and services that are both relatively expensive and goods and services that are relatively cheap.
b. That the purchasing power of a currency is relatively stable over time.
c. That people are willing to accept a currency in the future as compensation for debts accrued earlier.
d. That a currency is widely accepted in exchange for goods and services and therefore makes economic transactions easier.

Two firms, a and b, each currently emit 100 tons of chemicals into the air. the government has decided to reduce the pollution and from now on will require a pollution permit for each ton of pollution emitted into the air. the government gives each firm 40 pollution permits, which it can either use or sell to the other firm. it costs firm a $200 for each ton of pollution that it eliminates before it is emitted into the air, and it costs firm b $100 for each ton of pollution that it eliminates before it is emitted into the air. after the two firms buy or sell pollution permits from each other, we would expect that firm a will emit a. 100 fewer tons of pollution into the air, and firm b will emit 20 fewer tons of pollution into the air. b. 20 more tons of pollution into the air, and firm b will emit 100 fewer tons of pollution into the air. c. 50 fewer tons of pollution into the air, and firm b will emit 50 fewer tons of pollution into the air. d. 20 fewer tons of pollution into the air, and firm b will emit 100 fewer tons of pollution into the air.