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: a car travels at a speed of 12 miles per hour . how far will it travel in 5 hours ? 
Options: a ) 50 miles , b ) 60 miles , c ) 72 miles , d ) 22 miles , e ) 62 miles
Example Output: b

Example Input: Problem: in traveling from a dormitory to a certain city , a student went 1 / 5 of the way by foot , 2 / 3 of the way by bus , and the remaining 4 kilometers by car . what is the distance , in kilometers , from the dormitory to the city ? 
Options: a ) 30 , b ) 45 , c ) 60 , d ) 90 , e ) 120
Example Output: a

Example Input: Problem: a train crosses a platform of 110 m in 15 sec , same train crosses another platform of length 250 m in 20 sec . then find the length of the train ? 
Options: a ) 150 , b ) 88 , c ) 77 , d ) 310 , e ) 52
Example Output:
d