Which of the following accounts for the increase o

单项选择题

The case for college has been accepted without question for more than a generation. All high school graduates ought to go, says conventional wisdom and statistical evidence, because college will help them earn more money, become "better" people, and learn to be more responsible citizens than those who don"t go.
But college has never been able to work its magic for everyone. And now that close to half our high school graduates are attending, those who don"t fit the pattern are becoming more numerous, and more obvious. College graduates are selling shoes and driving taxis, and college students interfere with each other"s experiments and write false letters of recommendation in the intense competition for admission to graduate school. Others find no stimulation in their studies, and drop out—often encouraged by college administrators.
Some observers say the fault is with the young people themselves—they are spoiled and they are expecting too much. But that"s condemnation of the students as a whole, and doesn"t explain all campus unhappiness. Others blame the state of the world, and they are partly right. We"ve been told that young people have to go to college because our economy can"t absorb an army of untrained eighteen-year-olds. But disappointed graduates are learning that it can no longer absorb an army of trained twenty-two-year olds, either.
Some adventuresome educators and campus watchers have openly begun to suggest that college may not be the best, the proper, the only place for every young person after the completion of high school. We may have been looking at all those surveys and statistics upside down, it seems, and through the rosy glow of our own remembered college experiences. Perhaps college doesn"t make people intelligent, ambitious, happy, liberal, or quick to learn things—maybe it"s just the other way around, and intelligent, ambitious, happy, liberal, quick-learning people are merely the ones who have been attracted to college in the first place. And perhaps all those successful college graduates would have been successful whether they had gone to college or not. This is heresy to those of us who have been brought up to believe that if a little schooling is good, more has to be much better. But contrary evidence is beginning to mount up.

Which of the following accounts for the increase of the drop-out rate of college students according to the passage

A．Some college students want to make a living earlier.
B．Young people are disappointed with the teaching method at college.
C．College students are scared by the tough competition for admission to graduate school.
D．Some college students find little motivation in their studies.