【单选题】

B

There are colleges that have four-year graduation rates in the single digits. A 30% rate isn' t at all unusual, especially among regional public universities.
If you are applying to colleges, probably your goal is to get a college degree. Some schools are much more successful at graduating students than others. If the majority of the students at a college don' t graduate in four years, then they are spending more money for a goal that will evade them.
When you are calculating the cost of a college degree, you should take graduate rates into ac-count. If most students take five or six years to graduate, you shouldn' t plan on increased earning potential because of your degree.
Make sure you put graduation rates into context. There are often good reasons why some schools have larger graduation rates than others.
Professional progress in fields such as engineering, nursing and education are more likely to take five years than many other fields in the humanities, science and social science.
Many state universities have a large percentage of commuting students, working students and students with families. The demands on these students often making graduating in four years difficult.
These schools provide an important role by making college accessible to all, at the same time,they will often admit students who are entirely unprepared for the demands of college academics.
  What can we know from the first paragraph?
A. Four-year graduation rate is not lower than 30 percent
B. Both getting into colleges and graduating from them are easy
C. It is very hard to get a diploma in some public universities in America
D. It is common that 70% are not willing to go to universities