Choice "B" is correct. Under monopoly, strategic plans ignore market share and focus on profitability from production levels that will maximize profits.Choice "d" is incorrect. Continuous price responses to maintain market share is a characteristic of perfect competition.Choice "c" is incorrect. Under monopolistic competition, strategic plans include maintaining the market share (as with pure competition), but they also likely include plans for enhanced product differentiation and allocation of resources to advertising, product research, etc.Choice "a" is incorrect. Coordinating production volume and price changes along with product differentiation is a characteristic of oligopoly.