Explanation
Correct answer: B.
Choice B is the best answer because it most logically completes the text’s discussion of business marketing practices. In this context, "optimize" means make the most effective possible use of available opportunities. The text indicates that though businesses typically try to promote themselves, they don’t always make use of effective tools for doing so, pointing to research showing that 33 percent of restaurants failed to use a free listing service that increased revenue by 5 percent on average for restaurants that did use the service. The text therefore suggests that by foregoing a free and effective marketing tool, some businesses aren’t making the best use of, or optimizing, marketing opportunities.
Why the other choices are wrong
Choice A
Choice A is incorrect because in this context, "adorn" would mean decorate or enhance the appearance of, and there’s nothing in the text to suggest that by failing to use a free and effective promotional tool, some businesses aren’t enhancing the appearance of their own marketing. The example in the text illustrates that some businesses aren’t utilizing an effective marketing opportunity, not that they aren’t improving the appearance of their marketing.
Choice C
Choice C is incorrect because in this context, "endorse" would mean openly approve or recommend, and the text’s discussion of the fact that some businesses have overlooked an effective marketing tool doesn’t support the idea that those businesses therefore don’t approve of their own marketing.
Choice D
Choice D is incorrect because in this context, saying that businesses don’t "counteract" their marketing would suggest that they don’t actively undermine it or make it ineffective. The text begins by stating that businesses typically try to promote themselves but then continues to imply that some businesses fail to take advantage of good opportunities to do so, citing the example of businesses that failed to use a free and effective marketing tool. Though it’s possible that those businesses that did use the site therefore didn’t unintentionally counteract their own marketing, the first sentence conveys that the text’s focus is on things that some businesses do and that some businesses don’t do when trying to promote themselves, and it wouldn’t make sense to say that any businesses would actively try to undermine their own marketing in pursuit of that goal.