Correct answer is A
Explanation:
The Substring method is used to extract a portion of a string based on the specified start index and length.
strinput.LastIndexOf("_") returns the index of the last occurrence of the underscore "_" character in the string.
Adding 1 to the index (strinput.LastIndexOf("_")+1) will move the starting position to the character right after the underscore.
The second argument, 8, indicates the length of the substring to extract, which in this case is 8 characters representing the date "MMddyyyy" (i.e., the month, day, and year).
By using strinput.Substring(strInput.LastIndexOf("_")+1,8), you can extract the date portion from the file name.
Therefore, the correct choice is option A: strinput.Substring(strInput.LastIndexOf("_")+1,8).