Task: Question Answering
Input (English): Problem: when 242 is divided by a certain divisor the remainder obtained is 8 . when 698 is divided by the same divisor the remainder obtained is 9 . when the sum of the two numbers 242 and 698 is divided by the divisor , the remainder obtained is 4 . what is the value of the divisor ? 
Options: a ) 11 , b ) 17 , c ) 13 , d ) 23 , e ) none of these
Output (English): c