public static Base ChildofBase(Base papa)
{
ChildA r = new ChildA();
r.Prop1 = papa.Prop1;
//r.Prop2 = papa.Prop2; // Error: base.Prop2 is private
return(r);
}
static void Main(string[] args)
{
// ChildA childa = new Base("", ""); // Error: Can not implicitly convert type
ChildA childa = new ChildA();
// ChildB childb = childa; // Error: Can not implicitly convert type
//var res = childa.Prop4; // Error: Prop4 is protected
Console.ReadLine();
}