Which of the following statements is correct about the using statement used in C#.NET?

• using statement can be placed anywhere in the C#.NET source code file.
• It is permitted to define a member at namespace level as a using alias.
• A C#.NET source code file can contain any number of using statement.
• By using using statement it is possible to create an alias for the namespace but not for the namespace element.
• By using using statement it is possible to create an alias for the namespace element but not for the namespace.