The access specifier that gives least accessibility is:

1. package
2. public
3. protected
4. private

private

Reason — In Java, access specifiers determine the visibility or accessibility of classes, methods, and variables. The three main access specifiers are:

1. public: Accessible from anywhere in the program.
2. protected: Accessible within the same package and by subclasses even if they are in different packages.
3. private: Accessible only within the same class.

private gives least accessibility as it provides the most restricted access.