Which of the following are necessary for Run-time Polymorphism? 1 The overridden base method must be virtual, abstract or override. 2 Both the override method and the virtual method must have the same access level modifier. 3 An override declarat

Which of the following are necessary for Run-time Polymorphism?

1 The overridden base method must be virtual, abstract or override.

2 Both the override method and the virtual method must have the same access level modifier.

3 An override declaration can change the accessibility of the virtual method.

4 An abstract inherited property cannot be overridden in a derived class.

5 An abstract method is implicitly a virtual method.