What does the 'public' access modifier indicate in object-oriented programming?

The 'public' access modifier in object-oriented programming signifies that a class, method, or variable can be accessed from any other class in the program. This means there are no restrictions on access based on class hierarchy or package encapsulation.

When a component is marked as public, it is meant to be accessible to all other classes, regardless of whether they belong to the same package or a different one. This is especially useful in APIs and libraries where you want certain functionalities to be widely available to other developers or users of the code.

The other options each describe different access levels: the first option describes private access, which only allows access from within the same class; the second describes protected access, which is limited to the class and its subclasses; and the last option refers to package-private access, where access is restricted to classes within the same package. Therefore, the characterization of 'public' as universally accessible makes option C the correct explanation of this access modifier.