A positive static margin?

Which of the following statements is false? a. a class can directly inherit from class object. b. if the class you're inheriting from declares instance variables as private, the inherited class can access those instance variables directly. c. a class's instance variables are normally declared private to enforce good software engineering. d. it's often much more efficient to create a class by inheriting from a similar class than to create the class by writing every line of code the new class requires.