Base class referring to an instance of a derived class

what are you trying to achieve, because you cant declear Person p = new Student();

do u want to access variables that are in the Base class.

And to answer your Question you cant. if im getting your question correctly.

but for instance you can do this:

internal class A
    {
        public static void Aa()
        {
            Console.WriteLine("Base Class!");
        }
    }
    internal class B:A
    {
        public static void Bb()
        {
            Console.WriteLine("Dervide Class!");
        }
    }
    class Program
    {
        static void Main(string[] args)
        {
            B.Aa();//correct
            B base = new A();//incorrect
            Console.ReadLine();
        }
    }