A.public int compareTo（Object o）{/* more code here */}
B.public int compareTo（Score other）{/* more code here */}
C.public int compare（Score s1， Score s2）{/* more code here */}
D.public int compare（Object o1， Object o2）{/* more code here */}

A.The equals method does NOT properly override the Object.equals method.
B.Compilation fails because the private attribute p.name cannot be accessed in line 5.
C.To work correctly with hash-based data structures， this class must also implement the hashCode method.
D.When adding Person objects to a java.util.Set collection， the equals method in line 4 will prevent duplicates.