Levying environmental taxes and creating cap-and-trade quotas for emissions are both methods governments may use to reduce negative externalities. Which of the following best explains the economic rationale behind these policies?The policies ____. a. decrease the marginal costs of pollution for the firms while increasing revenue for governments b. place a monetary price on social costs so firms can guage their true costs accordingly c. All of these answers d. place a monetary price on social costs so firms can guage their true costs accordingly