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 garden , there are 10 rows and 12 columns of mango trees . the distance between the two trees is 2 metres and a distance of one metre is left from all sides of the boundary of the garden . the length of the garden is ? 
Options: a ) 12 , b ) 27 , c ) 24 , d ) 29 , e ) 11
Example Output: c

Example Input: Problem: a train speeds past a pole in 15 seconds and a platform 100 m long in 30 seconds . its length is ? 
Options: a ) 188 m , b ) 876 m , c ) 251 m , d ) 200 m , e ) 145 m
Example Output:
d