Which of the following would most likely cause a firm's cost curve to shift downward?

Which of the following statements is true?

A) A decrease in demand causes equilibrium price to fall; the decrease in price then results in a decrease in quantity supplied. B) If both demand and supply increase, there must be an increase in equilibrium price; equilibrium quantity may either increase or decrease. C) If demand decreases and supply increases one cannot determine if equilibrium price will increase or decrease without knowing which change is greater. D) A decrease in demand causes a decrease in equilibrium price; the decrease in price causes supply to decrease.

An increase in the amount of resources would shift the long-run aggregate supply curve:

A) rightward. B) leftward. C) no shift. D) none of the above.