Which of the following statements is correct?

1. Classes must belong to a namespace, whereas structures need not.
2. Every class, struct, enum, delegate and interlace has to belong to some or the other namespace.
3. All elements of the namespace have to belong to one file.
4. If not mentioned, a namespace takes the name of the current project.
5. The namespace should be imported to be able to use the elements in it.

1. All operators in C#.NET can be overloaded.
2. We can use the new modifier to modify a nested type if the nested type is hiding another type.
3. In case of operator overloading all parameters must be of the different type than the class or struct that declares the operator.
4. Method overloading is used to create several methods with the same name that performs similar tasks on similar data types.
5. Operator overloading permits the use of symbols to represent computations for a type.

1. true
2. false
3. +
4. new
5. is

1. true
2. false
3. new
4. ~
5. sizeof

public class Sample
{
    public int x;
    public virtual void fun()
    { }
}
public class DerivedSample : Sample
{
    new public void fun()
    { }
}