C# quiz. <PRE> <CODE class="csharp"> public abstract class

 
public abstract class A {
   public string PublicPrint() { 
      return Print(); 
   } 
 
   protected virtual string Print() {
        return "A"; 
   } 
}
 public class B : A { } 
 public class C : B { 
     protected override string Print() { 
         return "C"; 
     } 
}

What will be the result of the following code execution?

 
A ac = new C(); 
Console.WriteLine(ac.PublicPrint());

Compilation error
A
C
Runtime error

Explanation

This question is about basic rule of polymorphism. Code is calling an overloaded method. This method must be marked as virtual in a base class and must have "override" keyword in its signature in derived class.