In this task, you need to answer the given multiple-choice question on the physics. Classify your answers into 'a', 'b', 'c', 'd', and 'e'.

Example Input: Problem: the sum of two consecutive integers is 15 . find the numbers . 
Options: a ) 17 , 18 , b ) 7 , 8 , c ) 5 , 6 , d ) 1 , 2 , e ) 8 , 9
Example Output: b

Example Input: Problem: jim drove 768 miles of a 1200 miles journey . how many more miles does he need to drive to finish his journey ? 
Options: a ) 432 miles , b ) 651 miles , c ) 387 miles , d ) 954 miles , e ) 556 miles
Example Output: a

Example Input: Problem: perimeter of the back wheel = 9 feet , front wheel = 7 feet on a certain distance , the front wheel gets 10 revolutions more than the back wheel . what is the distance ? 
Options: a ) 315 , b ) 325 , c ) 335 , d ) 345 , e ) 305
Example Output:
a