Question 4 is based on the news report you have just heard.

听力原文

    (3) Fast food, it turns out, isn’t quite as fast as it used to be. A new study finds that McDonald’s posted a slowest drive-through times since this survey was first conducted 15 years ago. At McDonald’s, customers will spend on average 3 minutes and 9 seconds from the time they place their orders until they receive their food. That’s about 10 seconds more than the industry average—and a lot slower than a decade ago, according to the study, which was commissioned by QSR, an industry trade publication. (3) And McDonald’s wasn’t alone in slowing down. Other chains also saw their drive-through performance slow down. (4) Among the reasons for the slower service: Today there are more choices on the menu, and the products themselves are more complex and take longer to prepare. Speed, of course, is essential to the drive-through experience and drive-throughs are hugely important to chains such as McDonald’s, Burger King and Taco Bell. “Usually the drive-through accounts for 60 to 70 percent of all business that goes through a fast-food restaurant,” notes Sam Oches, the editor of QSR. Of course, consumers also want their orders prepared correctly and on that score, Oches says, “accuracy is still really high.”

4. What has slow down McDonald’s drive-through service?

解析：C。本题目为细节题。问题为：什么减缓了麦当劳的直通服务？根据原文，免下车服务变慢的原因是菜单上出现了更多的产品以供选择，而产品本身更复杂，需要更长的时间来准备。选项中increaseed variety是原文中more choices的同义替换，故正确答案为C。