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 certain car uses 12 gallons of gasoline in traveling 180 miles . in order for the car to travel the same distance using 10 gallons of gasoline , by how many miles per gallon must the car ’ s gas mileage be increased ? 
Options: a ) 2 , b ) 3 , c ) 6 , d ) 8 , e ) 10
Example Output: b

Example Input: Problem: in a kilometer race , a beats b by 40 meters or 10 seconds . what time does a take to complete the race ? 
Options: a ) 290 sec , b ) 190 sec , c ) 199 sec , d ) 192 sec , e ) 240 sec
Example Output: e

Example Input: Problem: a and b can do a work in 25 days and 10 days respectively . a starts the work and b joins him after 2 days . in how many days can they complete the remaining work ? 
Options: a ) 4.28 days , b ) 4.38 days , c ) 5.28 days , d ) 6.28 days , e ) 2.28 days
Example Output:
a