What type of access control does a "protected" variable have in an object-oriented language?

A "protected" variable in an object-oriented language is designed to provide a specific level of access that promotes encapsulation while enabling class inheritance. When a variable is declared as protected, it allows access within the class it is defined in, as well as by any subclass of that class. This means that subclassing is a critical aspect of how protected access is utilized—subclasses can inherit and use the protected variable even if they reside in different packages.

This access control is particularly useful for creating a hierarchy of classes where derived classes can make use of the properties and behaviors defined in a parent class while still keeping those properties shielded from direct access by unrelated classes. Thus, by restricting access to the class itself and its subclasses, the protected modifier enhances both the reusability and security of the variables in an object-oriented design.

In this context, options regarding accessibility by any class in the project or only within the same package do not apply to protected variables. Additionally, the notion that protected variables are not accessible within the same package is incorrect, as they are indeed accessible to other classes in the same package if those classes do not extend the original class.