Which of the following markets is closest to a monopoly?

The figure above shows Ronald's budget line. He has a weekly income of $20, which he spends on hotdogs and hamburgers. Ronald's real income in terms of hamburgers ________

A) depends on the quantity of hamburgers consumed B) depends on the quantity of hotdogs consumed C) is $20 D) is 10 hamburgers

According to the Laffer curve, we know with certainty that an increase in the tax rate will

A) cause tax revenue to increase. B) cause tax revenue to decrease. C) have no effect on tax revenue. D) cause tax revenue to increase, decrease, or remain unchanged.