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: if the wheel is 12 cm then the number of revolutions to cover a distance of 1240 cm is ? 
Options: a ) 11 , b ) 14 , c ) 16 , d ) 12 , e ) 19
Example Output: c

Example Input: Problem: a garrison of 1850 men has provisions for 28 days . at the end of 12 days , a reinforcement arrives , and it is now found that the provisions will last only for 10 days more . what is the reinforcement ? 
Options: a ) 1850 , b ) 2960 , c ) 3000 , d ) 1110 , e ) 1712
Example Output: d

Example Input: Problem: ajay can walk 10 km in 1 hour . in how many hours he can walk 50 km ? 
Options: a ) 5 hrs , b ) 10 hrs , c ) 15 hrs , d ) 20 hrs , e ) 30 hrs
Example Output:
a