Choice B is the best answer because details in the third paragraph (lines 20–31) strongly suggest that researchers (“we”) at the Martin Prosperity Institute assume that shorter commutes will lead to more productive time for workers. The author notes that “across the country, commuting wastes 4.2 billion hours of work time annually” and that “the overall cost to the U.S. economy is nearly $90 billion when lost productivity and wasted fuel are taken into account” (lines 24–27). Given also that those at the institute “calculate that every minute shaved off America’s commuting time is worth $19.5 billion in value added to the economy” (lines 28–29), it can reasonably be concluded that some of that added value is from heightened worker productivity.

Choice A is not the best answer because there is no evidence in the passage that researchers at the Martin Prosperity Institute assume that employees who work from home are more valuable to their employers than employees who commute. Although the passage does criticize long commutes, it does not propose working from home as a solution.

Choice C is not the best answer because there is no evidence in the passage that researchers at the Martin Prosperity Institute assume that employees can conduct business activities, such as composing memos or joining conference calls, while commuting. The passage does discuss commuting in some detail, but it does not mention activities that commuters can or should be undertaking while commuting, and it generally portrays commuting time as lost or wasted time.

Choice D is not the best answer because there is no evidence in the passage that researchers at the Martin Prosperity Institute assume that employees who have lengthy commutes tend to make more money than employees who have shorter commutes. The passage does not draw any clear links between the amount of money employees make and the commutes they have.