A budget line is the locus of all points representing every input combination of inputs that the producer can afford to buy with a given amount of money and given input prices

Prices in an oligopoly industry tend to be higher than in a competitive industry

Indicate whether the statement is true or false

Suppose the government imposes a $2 per-unit tax on an item whose production creates a negative externality. Suppose the $2 is exactly the value of the external cost. If the government uses the tax revenue to clean up pollution created by this production,

a. an optimal allocation of resources has been achieved b. the market's equilibrium price is an efficient one c. no externalities exist d. there is no market failure e. it is clear that obligatory controls have worked