Assume the Environmental Protection Agency imposes an excise tax on polluting firms. In which of the following situations would we expect the additional costs to be borne most heavily by consumers?

A. demand is highly elastic and supply is highly inelastic
B. demand and supply are both highly elastic
C. demand and supply are both highly inelastic
D. demand is highly inelastic and supply is highly elastic

answer: D. demand is highly inelastic and supply is highly elastic