Given a class whose instances， when found in a collection of objects， are sorted by using the compareTo（） method， which two statements are true？（）

• A、The class implements java.lang.Comparable.
• B、The class implements java.util.Comparator.
• C、The interface used to implement sorting allows this class to define only one sort sequence.
• D、The interface used to implement sorting allows this class to define many different sort sequences.