The social disadvanatges of a purely competitive market situation do not include which one of the following?
a. All of the above are dsiadvantages of pure competition.
b. The industry is slow in adopting improved technology tht has already been developed.
c. The product lacks the variety desired by the public, because of the homogeneity in production.
d. Like industries in other market situations, purely competitive firm cannot include external cost in their costs and revenues.