Explanation
Correct answer: C.
Choice C is the best answer because it best describes the function of the underlined portion in the text as a whole. The underlined portion states that people commonly believe happiness is the ideal emotional state. However, the text then notes that recent research suggests that negative emotions can be beneficial, as demonstrated by an experiment by Heather Lench in which participants primed to feel anger did better at solving puzzles than did those primed to feel other emotions. This finding calls into question the belief that happiness is always the ideal state. Thus, the underlined portion notes a generally accepted belief that is called into question by a finding from the experiment.
Why the other choices are wrong
Choice A
Choice A is incorrect because the study does not address why people assume happiness is ideal. Rather, the text indicates the study was designed to test whether anger can contribute to problem-solving abilities.
Choice B
Choice B is incorrect because rather than underlying the study’s hypothesis that anger could be beneficial in some circumstances, the underlined portion presents the widely held belief that happiness is always preferable to negative emotions, which directly conflicts with that hypothesis.
Choice D
Choice D is incorrect because the underlined portion presents a common belief that happiness is the ideal emotional state, not an explanation for the participants’ behavior in the experiment. The text reports that participants in the anger condition performed better on the puzzles but does not explain the psychological reason for this outcome.