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: walking with 4 / 5 of my usual speed , i arrive at the bus stop 7 minutes later than normal . how many minutes does it take to walk to the bus stop at my usual speed ? 
Options: a ) 12 , b ) 16 , c ) 20 , d ) 24 , e ) 28
Example Output: e

Example Input: Problem: a flagpole 18 meters high casts a shadow of length 45 meters . if a building under similar conditions casts a shadow of length 55 meters , what is the height of the building ( in meters ) ? 
Options: a ) 20 , b ) 22 , c ) 24 , d ) 26 , e ) 28
Example Output: b

Example Input: Problem: sides of a rectangular park are in the ratio 3 : 2 and its area is 1536 sq m , the cost of fencing it at 50 ps per meter is ? 
Options: a ) 51 , b ) 1287 , c ) 125 , d ) 988 , e ) 271
Example Output:
a