Even though a default initialization of a salaried employee is not one of the responsibilities given, the SalariedEmployee class should explicitly define a default constructor. Why?

a. Because a class that contains any constructors must explicitly define a default constructor.

b. For the sake of future subclasses of SalariedEmployee.

c. Because the FullTimeEmployee class has a default constructor.

d. Because the HourlyEmployee class has a default constructor.