using Python plz solve Q9 (A,B, and C)

9. Suppose you type a 14-digit credit card number into a Web site, but mistype one of the digits or inadvertently interchange two adjacent digits. The Web site will perform a validation check that always detects the first type of errors and nearly always detects the second type of error. The validation check is as follows: a. Starting with the leftmost bit, double it and then double every other digit after it. However, if any of the doubled digits is a two-digit number, subtract 9 from it. Then sum these new digits. For instance, if the credit card number is 58667936100244, then the digits considered are 5,6,7,3,1,0,4, their new replacements are 1,3,5,6,2,0,8, and the sum of the replacements is 25. b. Sum together the remaining seven digits from the credit card number. That is, the digits in the odd-numbered positions. With the credit card number above, we obtain 8+6+9+6+0+2+4-35 4