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 can complete a work in 12 days and b can do the same work in 8 days . if a after doing 2 days , leaves the work , find in how many days b will do the remaining work ? 
Options: a ) 2 days , b ) 4 1 / 2 days , c ) 6 1 / 2 days , d ) 7 3 / 4 days , e ) 10 days
Example Output: c

Example Input: Problem: a train running at the speed of 60 km / hr crosses a pole in 6 sec . what is the length of the train ? 
Options: a ) 356 , b ) 278 , c ) 127 , d ) 100 , e ) 150
Example Output: d

Example Input: Problem: a clock shows the time as 9 a . m . if the minute hand gains 5 minutes every hour , how many minutes will the clock gain by 6 p . m . ? 
Options: a ) 30 min , b ) 35 min , c ) 45 min , d ) 50 min , e ) 55 min
Example Output:
c