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'.

Input: Consider Input: Problem: the ratio between the speeds of two trains is 7 : 8 . if the second train runs 400 km in 4 hours , what is the the speed of the first train ? 
Options: a ) 87.0 , b ) 87.5 , c ) 87.2 , d ) 87.1 , e ) 87.4

Output: b


Input: Consider Input: Problem: a train 140 m long running at 84 kmph crosses a platform in 16 sec . what is the length of the platform ? 
Options: a ) 287 , b ) 298 , c ) 233 , d ) 726 , e ) 267

Output: c


Input: Consider Input: Problem: a car gets 40 kilometers per gallon of gasoline . how many gallons of gasoline would the car need to travel 160 kilometers ? 
Options: a ) 8 gallons , b ) 4 gallons , c ) 6 gallons , d ) 5.5 gallons , e ) 10 gallons


Output: b