Namespaces - Programming

Q1:

Which of the following statments are the correct way to call the method Issue() defined in the code snippet given below?
namespace College
{
    namespace Lib
    {
        class Book
        {
            public void Issue()
            {
                // Implementation code
            }
        }
        class Journal
        {
            public void Issue()
            {
                // Implementation code
            }
        }
    }
}
  1. College.Lib.Book b = new College.Lib.Book(); 
    b.Issue();
  2. Book b = new Book(); 
    b.Issue();
  3. using College.Lib; 
    Book b = new Book(); 
    b.Issue();
  4. using College;
    Lib.Book b = new Lib.Book(); 
    b.Issue();
  5. using College.Lib.Book; 
    Book b = new Book(); 
    b.Issue();

A 1, 3

B 2, 4

C 3

D 4, 5

ANS:A - 1, 3

In the first statement along with the name space initiation we assigning variable 'b' as a new class and executing it with the specified class b. Issue for book.

In the fourth statement 4 we are declaring class and accessing with a new variable and executing with book class.