Can you change the access modifier of a base class method in a derived class? (Hiding vs Overriding)

Generally, a derived class cannot override a base method with a more restrictive access level because that would violate substitutability. For example, a public base method cannot normally become protected or private in an override. Languages have specific rules around increasing visibility, method hiding and overriding. Hiding creates a new member in the derived class rather than participating in runtime polymorphism, so it should be used deliberately and not as a substitute for proper overriding.