单选题：Questions are based on the followingpassage.　　Byalmost any

Questions are based on the followingpassage.
　　Byalmost any measure, there is a boom in Intemet-based instruction. In just a fewyears,34 percent ofAmerican universities have begun offering some form ofdistance learning (DL), and among the larger schools,it's closer to 90 percent.If you doubt the popularity of the trend, you probably haven't heard of theUniversity ofPhoenix. It grants degrees entirely on the basis of onlineinstruction. It enrolls 90,000 students, a statistic used tosupport its claimto be the largest private university in the country.
　　Whilethe kinds of instruction offered in these programs will differ, DL usuallysignifies a course in which theinstructors post syllabi( 课程大纲), reading assignments, and schedules on Websites, and students sendin theirassignments by e-mail. Generally speaking, face-to-face communicationwith an instructor is minimized oreliminated altogether.
　　Theattraction for students might at first seem obvious. Primarily, there's theconvenience promised by courseson the Net: you can do the work, as they say, inyour pajamas ( 睡衣). But figures indicate that the reducedeffortresults in a reduced commitment to the course. While dropout rates for allfreshmen at American universitiesis around 20 percent, the rate for onlinestudents is 35 percent. Students themselves seem to understand theweaknessesinherent in the setup. In a survey conducted for eComell, the DL division ofComell University, lessthan a third of the respondents expected the quality ofthe online course to be as good as the classroom course.
　　Clearly,from the schools' perspective, there's a lot of money to be saved. Althoughsome of the moreambitious programs require new investments in servers andnetworks to support collaborative software, most DLcourses can run on existingor minimally upgraded(升级)systems. The more students who enroll in acourse butdon't come to campus, the more the school saves on keeping the lightson in the classrooms, paying doorkeepers,and maintaining parking lots. Andthere's evidence that instructors must work harder to run a DL course foravariety of reasons, they won't be paid any more, and might well be paid less.
What is the most striking feature of theUniversity of Phoenix? A．Allits courses are offered online.
B．Itsonline courses are of the best quality.
C．It boasts the largest number of studentson campus.
D．Anyone taking its online courses is sure to get a degree.