Which two actions will improve the encapsulation of a class?

Changing a field's access modifier from public to private restricts direct external access, forcing consumers to interact with the field through controlled methods (getters/setters), thereby protecting the internal state from unintended modifications.

Removing the public modifier from a class makes it package-private, limiting its visibility but not directly improving the encapsulation of its internal fields or methods from other classes within the same package.

Changing a method's return type to void only signifies that the method does not return a value; it does not inherently restrict access to internal data or control state modifications, thus not directly improving encapsulation.

Returning a copy of an internal mutable collection prevents external code from directly modifying the object's internal data structure, ensuring that any changes made externally do not affect the object's encapsulated state without its explicit control.