Given the following classes: public class Employee { public int salary; } public class Manager extends Employee { public int budget; } public class Director extends Manager { public int…

Question

Options

• Amanager .stockoption = 500;
• Bdirector .stockoption = 1_000;
• Cdirector .salary = 50_000;
• Demployee .budget = 200_000;
• Eemployee .salary = 50_000;
• Fmanager .budget = 1_000_000;

• A
  71% (15)
• C
  10% (2)
• E
  14% (3)
• F
  5% (1)

Explanation

A and D are the two options that fail to compile, because they attempt to access fields that don't exist on the declared type of the variable.

• A fails: manager is declared as type Manager, and Manager only inherits salary from Employee and defines budget - stockoptions belongs to Director (a subclass), and a parent type cannot access a child's members.
• D fails: employee is declared as type Employee, which only has salary - budget is defined in Manager (a subclass), so it's inaccessible via an Employee reference.
• B passes: director is declared as Director, which does define stockoptions - valid access.
• C passes: director inherits salary all the way up from Employee - subclasses inherit all non-private members.
• E passes: employee.salary directly accesses its own field.
• F passes: manager.budget accesses Manager's own field.

Memory tip: Inheritance flows down - a variable can only see fields at its own level and above (ancestors), never below (descendants). Think of it as "a Manager knows about Employee things, but not Director things."

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