The 3 digit card security code (CSC) on a credit card helps to protect against credit card fraud. Write a simple function check_csc (code) that checks if a given code is valid. The code is valid if it is three characters long and all the three characters entered are digits between 0 and 9. If the CSC is valid, your function must return True. Otherwise it must return False. Your function should work like this: >>> check_csc ('023') True >>> check_csc ('23') False >>> check_csc ('Ab3') False >>> check_csc('') False