Beginning from a Long Run Equilibrium in an Increasing Cost

Beginning from a long run equilibrium in an increasing cost industry,if there is a substantial,permanent fall in demand for industry output:

A) firms will leave the industry, the quantity produced will fall, and prices will end up lower than their initial long run equilibrium level.
B) firms will leave the industry, the quantity produced will fall, and prices will end up higher than their initial long run equilibrium level.
C) firms will leave the industry, the quantity produced will fall, and prices will end up at the same level as their initial long run equilibrium level.
D) firms will enter the industry, the quantity produced will rise, and prices will end up lower than their initial long run equilibrium level.