题目选项分析

Which of the following most logically completes the argument?

The growing popularity of computer-based activities was widely predicted to result in a corresponding decline in television viewing. Recent studies have found that, in the United States, people who own computers watch, on average, significantly less television than people who do not own computers. In itself, however, this finding does very little to show that computer use tends to reduce television viewing time, since __________.

【选项】computer owners in the United States predominantly belong to demographic groups that have long been known to spend less time watching television than the population as a whole does