10. abstract public class Employee {  11. protected abstract double getSalesAmount（）；  12. public double getCommision（） {  13. return getSalesAmount（） * 0.15；  14. }  15. }  16. class Sales extends Employee {  17. // insert method here  18. }  Which two methods， inserted independently at line 17， correctly complete the Sales class？（）

• A、 double getSalesAmount（） { return 1230.45； }
• B、 public double getSalesAmount（） { return 1230.45； }
• C、 private double getSalesAmount（） { return 1230.45； }
• D、 protected double getSalesAmount（） { return 1230.45； }