C#.NET Namespaces — which statement is correct about nesting namespaces?

Difficulty: Easy

• Namespaces can be nested only up to level 5.
• A namespace cannot be nested.
• There is no limit on the number of levels while nesting namespaces.
• If namespaces are nested, using statement is required for inner elements.
• Nesting of namespaces is permitted only if all inner namespaces are in the same file.