5. An advertisement designed to convince readers of the great durability of automobiles manufactured by the Deluxe Motor Car Company cites as evidence the fact that over half of all automobiles built by the company since 1970 are still on the road today， compared to no more than a third for any other manufacturer.

　　Which of the following， if true， most strongly supports the advertisement's argument？

　　（A） After taking inflation into account， a new Deluxe automobile costs only slightly more than a new model did in 1970.

　　（B） The number of automobiles built by Deluxe each year has not increased sharply since 1970.

　　（C） Owners of Deluxe automobiles typically keep their cars well maintained.

　　（D） Since 1970， Deluxe has made fewer changes in the automobiles it manufactures than other car companies have made in their automobiles.

　　（E） Deluxe automobiles have been selling at relatively stable prices in recent years.

　　6.Six months or so after getting a video recorder， many early buyers apparently lost interest in obtaining videos to watch on it. The trade of businesses selling and renting videos is still buoyant， because the number of homes with video recorders is still growing. But clearly， once the market for video recorders is saturated， businesses distributing videos face hard times.

　　Which of the following， if true， would most seriously weaken the conclusion above？

　　（A） The market for video recorders would not be considered saturated until there was one in 80 percent of homes.

　　（B） Among the items handled by video distributors are many films specifically produced as video features.

　　（C） Few of the early buyers of video recorders raised any complaints about performance aspects of the new product.

　　（D） The early buyers of a novel product are always people who are quick to acquire novelties， but also often as quick to tire of them.

　　（E） In a shrinking market， competition always intensifies and marginal businesses fail.