阅读下列短文，从每题所给的四个选项(A、B、C和D)中选出最佳选项。
C
Class Afloat is a Canadian school on a tall ship! The ship is 210 feet long and 30 feet wide, and it can take up to sixty students . The classrooms are well-equipped and comfortable, and there's even a library! It isn't necessary to know anything about sailing----students can learn on the ship.
Not all the students are Canadian. There's usually a mix of nationalities. This year, there are also students from Mexico, the US, Germany, and Turkey. There's a mix of ages too. There are high school students sixteen to eighteen years old, and first-year college students.
The teachers design special study programs for each student. Because the school is a ship, you can do some exciting classes,for example, Marine Biology (studying the animals and plants in the sea) and History of Geography courses about the places you visit. Students also learn all about sailing!
Students don't just study. They must also clean, cook and sail the ship. In their free time, students can rest, read, or watch a movie. In the evening, they relax with friends and have club meetings.
Every sixteen to twenty days, the ship stops in a port for three to six days. In port there's lots for the students to do-- homestays, camping trips, museum tours, cultural events, hiking, etc. They also go boating and do other water sports. Parents can meet up with the students in one port every term.
Students also take part in two volunteer programs in Senegal and the Dominican Republic. They help local families in different ways, for example, with basic health matters or starting a business. Students learn how, with just a little money and time, they can make changes that improve other people's lives.
C（金刚石），