Suppose a Perfectly Competitive Industry Is in Long-Run Equilibrium

Suppose a perfectly competitive industry is in long-run equilibrium.A new one-time cost-saving technology (which is freely available) is then developed and new plants are built.Eventually,a new long-run equilibrium will be established where

A) new plants employ the new technology,but existing plants continue to produce as long as they cover their fixed costs.
B) high-cost and low-cost firms exist side by side and market output will be higher.
C) the industry supply curve has shifted to the left and price and output are both higher.
D) all plants continue to operate until they are physically worn out as long as price is greater than the firm's average variable cost.
E) all plants use the new technology,and market output will be higher and price will be lower.