Which of the following does not apply to new feature Optional parameters in C# 4.0

Optional parameters can make your code more readable and easier to maintain, and can reduce the amount of typing you have to do

We can use optional parameters and no longer have to overload functions with a number of methods

Optional parameters are created in C# by specifying a default value and must appear after required parameters

Following is the way to specify optional parameters for function ReadFile static void ReadFile(string FileName:"", string OpenMode:"ReadOnly") {...}