Suppose four firms engage in price competition in a Bertrand setting where the lowest-price firm will capture the entire market. The firms differ with respect to their costs. Firm A's marginal cost per unit is $8, firm B's is $7, firm C's is $9, and firm D's is $7.50.
a. Which firm will serve the market? What price (approximately) will it charge?
b. Would your answer change if firms A and B had somewhat greater fixed costs of production than firms C and D?