Call a subroutine to prompt the user for a path/filename for an existing mono WAV file (you will use ts9_mono. wav to debug your program). Read this path/filename from the keyboard as a string, and store it in a 1-D 200 char array. Step 2) Check that the file extension (the 3-4 letters past the last period in the path/filename) is WAV or wav. If not, notify the user of his/her error, and re-prompt the user for a path/filename (i. e. call the subroutine in 1.) Here, you can see that you should be doing steps 1,2 (and 3) inside a loop that is exited when the conditions are met. Step 3) When the user has entered a WAV path/filename, open the file as "r+b" (read and write binary – this doesn’t create a file if it doesn’t exist; it doesn’t destroy the contents of the file upon opening if the file does exist). Check the file pointer to see if it is NULL. If so, notify the user, and re-prompt (i. e. call the subroutine in 1.) starting the process over. Step 4) If the WAV file is successfully opened, use fseek( ) to go to the correct location in the file and use fread( ) to read the following from the header: Audioformat, NumChannels BitsPerSample Subchunk2Size For example, NumChannels