If competition places discipline on costs, motivating firms to innovate and find more cost-effective ways to produce, which would then explain why in some markets a single firm without competitors will produce at a lower cost than if the firm faced competition?

there was no passage listed but using the process of elimination i'd say it was d. the high economy would do the opposite. i don't see how low prices would affect it. high unemployment is possible but i feel d is the better answer.

answer; ///(d); determining who competes most closely   with whom evaluating whether industry driving forces and competitive pressure favor some strategic groups and hurt others, and ascertaining whether the profit potential of different strategic groups varies due to the strengths and weaknesses in each groups respective market positions;

answer; the correct answer is (enforcement of regulations;