The article is mainly about______.

Câu hỏi: Read the following passage and mark the letter A, B, C, or D on your answer sheet to indicate the correct answer to each of the questions from 36 to 42.
For many American university students, the weeklong spring break holiday means an endless party on a sunny beach in Florida or Mexico. In Panama City Beach, Florida, a city with a permanent population of around 36,000, more than half a million university students arrive during the month of March to play and party, making it the number one spring break destination in the United States.
A weeklong drinking binge is not for anyone, however, and a growing number of American university students have found a way to make spring break matter. For them, joining or leading a group of volunteers to travel locally or internationally and work to alleviate problems such as poverty, homelessness, or environmental damage makes spring break a unique learning experience that university students can feel good about.
During one spring break week, students at James Madison University in Virginia participated in 15 "alternative spring break" trips to nearby states, three others to more distant parts of the United States, and five international trips. One group of JMU students traveled to Bogalusa, Louisiana, to help rebuild homes damaged by Hurricane Katrina. Another group traveled to Mississippi to organize creative activities for children living in a homless shelter. One group of students did go to Florida, but not to lie on the sand. They performed exhausting physical labor such as maintaining hiking trails and destroying invasive plant species that threaten the native Florida ecosystem.
Students who participate in alternative spring break projects find them very rewarding. While most university students have to get their degrees before they can start helping people, student volunteers are able to help people now. On the other hand, the accommodations are far from glamorous. Students often sleep on the floor of a school or spend the week camping in tents. But students only pay around $250 for meals and transportation, which is much less than some of their peers spend to travel to more traditional spring break hotspots.
Alternative spring break trips appear to be growing in popularity at universities across the United States. Students cite a number of reason for participating. Some appreciate the opportunity to socialize and meet new friends. Others want to exercise their beliefs about people's obligation to serve humanity and make the world a better place whatever their reason, these students have discovered something that gives them rich rewards along with a break from school work.
("Active Skills for Reading: Book 2" by Neil J.Anderson – Thompson, 2007)
The article is mainly about______.
A. sleeping on the floor or camping in tents.
B. alternative spring break trips.
C. drinking problems among university students.
D. spring break in Florida and Mexico