57. When Hawaii's Mt. Kiluea erupts violently, the demand on the part of tourists for sightseeing flights increases but the supply of pilots willing to provide these dangerous flights decreases. We can expect that, in this tourism market, the equilibrium A. price must rise and equilibrium quantity may rise, fall, or remain unchanged. B. price must fall, but equilibrium quantity may rise, fall, or remain unchanged. C. quantity must increase but equilibrium price may rise, fall, or remain unchanged. D. quantity must decrease but equilibrium price may rise, fall, or remain unchanged