单选题

下面代码输出的结果为

Question

下面代码输出的结果为:

import java.util.ArrayList
import java.util.Collections
import java.util.List
public class Test{
    public static void main(String[] args) {
        List<Student> students = new ArrayList<Student>()
        students.add(new Student(10))
        students.add(new Student(18))
        students.add(new Student(15))
        Collections.sort(students)
        System.out.print(students.get(1).age)
    }
}
class Student implements Comparable<Student> {
    Integer age
    public Student(Integer age) {
      this.age = age
    }
    public int compareTo(Student s) {
        return s.age.compareTo(this.age)
    }
}

A. 15

B. 10

C. 18

D. 编译失败