You are developing an application that includes the following code segment. (Line numbers
are included for reference only.)

You need to ensure that the application accepts only integer input and prompts the user
each time non-integer input is entered.
Which code segment should you add at line 19?

A.
If (!int.TryParse(sLine, out number))

B.
If ((number = Int32.Parse(sLine)) = = Single.NaN)

C.
If ((number = int.Parse (sLine)) > Int32.MaxValue)

D.
If (Int32.TryParse(sLine, out number))