Correct Answer - Option 1 : Buffer variable
The creation of a file variable will automatically create a special variable associated with it, called as buffer variable
Syntax
buffer-variable = file-variable '^' | file-variable '@'
Where file-variable is a reference to a file variable.
Important points
When a file variable is opened in read-only mode, the contents of the buffer variable associated with the file variable, will either be equal to the first value in the file or be undefined if the file is empty.
As the file is read, the contents of the buffer variable will always either be equal to the next value to be read from the file or be undefined if there is no next value to be read from the file
When a file variable is opened in write-only mode, the contents of the buffer variable associated with the file variable is initially undefined.
