Which class is extended by all other classes in Java?

• A. The Base class.
• B. The Super class.
• C. The Object class.
• D. The Main class.

Answer: (C)

In Java, every class inherits from the Object class, either directly or indirectly. The Object class is the root of the class hierarchy in Java, meaning that it is the superclass for all other classes. This means that all classes inherit common methods from the Object class, such as toString(), equals(), hashCode(), and many others.

When a class is created in Java, if no explicit superclass is defined, it automatically extends the Object class. This inheritance allows objects of any class to be treated as instances of Object, enabling polymorphism. For instance, you can store any object in a collection that is defined to hold Object types.

The other options are not applicable because:

• The Base class and Super class are general terms that could refer to any class that serves as a foundation for others, but they are not specific to Java's class hierarchy.

• The Main class typically refers to a class that contains the main method, which serves as the entry point for Java applications, but it is not a class from which all other classes extend.

Thus, the Object class serves as the universal ancestor in Java's class structure, reinforcing the principles of object-oriented programming.