The renewable energy company's new solar panel design proved to be remarkably efficient. It converted sunlight to electricity at nearly double the rate of conventional panels, representing a major advancement in sustainable technology.
As used in the text, what does the word "efficient" most nearly mean?
expensive
colorful
ancient
productive
Correct Answer: D
Choice D is the best answer. The passage explains that the panels converted sunlight at "nearly double the rate," indicating high output relative to input. "Productive" captures this sense of achieving more with the same resources.
Choice A is incorrect because "expensive" refers to cost, not performance. Choice B is incorrect because "colorful" describes appearance, irrelevant here. Choice C is incorrect because "ancient" refers to age, not function.