阅读和理解下面程序段:
class Manager extends Employee
public Manager(String n,double s,int year,int month,int day)
super(n,s,year,month,day);
bonus=0;
public double getSalary()
double baseSalary=super.gerSalary();
return baseSalary+bonus;
public void setBonus(double b)bonus=b;
private double bonus;
Manager是Employee的子类,其理由是
A.Manager的适用范围较宽
B.extends关键字声明
C.Manager的域减小了
D.雇员是一个经理