Q1:

Which of the following statements are correct?

1. An argument passed to a ref parameter need not be initialized first.
2. Variables passed as out arguments need to be initialized prior to being passed.
3. Argument that uses params keyword must be the last argument of variable argument list of a method.
4. Pass by reference eliminates the overhead of copying large data items.
5. To use a ref parameter only the calling method must explicitly use the ref keyword.