Jessica sees a search ad on her mobile phone for a restaurant. A button on the ad allows Jessica to click on the button and call the restaurant. This is a(n) Group of answer choices product listing ad (PLA) dynamic keyword insertion ad (DKI) click-to-call ad call-to-action ad (CTA)

Write a program that asks the user to enter the name of an input file. if the file does not exist, the program should prompt the user to enter the file name again. if the user types quit in any uppercase/lowercase combinations, then the program should exit without any further output.