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: ajay can walk 6 km in 1 hour . in how many hours he can walk 70 km ?
Options: a ) 5 hrs , b ) 11.6 hrs , c ) 15.6 hrs , d ) 20.1 hrs , e ) 30 hrs
Example Output: b

Example Input: Problem: if two girls starting from same point , walking in the opposite directions with 7 km / hr and 3 km / hr as average speeds respectively . then the distance between them after 12 hours is ?
Options: a ) 120 , b ) 121 , c ) 122 , d ) 123 , e ) 124
Example Output: a

Example Input: Problem: two trains are moving in opposite directions at 60 km / hr and 90 km / hr . their lengths are 2.10 km and 1.4 km respectively . the time taken by the slower train to cross the faster train in seconds is ?
Options: a ) 99 , b ) 277 , c ) 84 , d ) 96 , e ) 22
Example Output:
c