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 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: 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 man can row a distance of 5 km in 60 min with the help of the tide . the direction of the tide reverses with the same speed . now he travels a further 25 km in 10 hours . how much time he would have saved if the direction of tide has not changed ? 
Options: a ) 2 , b ) 5 , c ) 1 , d ) 6 , e ) 7
Example Output:
b