SAT English Practice Question

A study was done in which researchers tried to determine the most effective method for people to conserve energy. In the study, researchers asked participants to identify the most effective action that people can take to save energy. The team then classified each action as either an efficiency (using a more efficient appliance or lightbulb) or a curtailment (using a bike or public transportation, or turning off the lights).

1. A.For example, turning off the lights, which was selected by 19.6 percent of respondents, is a curtailment.
2. B.For example, turning off the lights—which was selected by 19.6 percent of respondents—is a curtailment.
3. C.For example, turning off the lights, which was selected by 19.6 percent of respondents, is a curtailment;
4. D.For example, turning off the lights, which was selected by 19.6 percent of respondents, is a curtailment—