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 tiger is chasing its prey at a constant speed . it entire body passes a blade of grass in 1 second . it then runs above a fallen tree trunk that is 20 meters long in 5 seconds . what is the length of the tiger ? 
Options: a ) 6 m , b ) 5 m , c ) 4 m , d ) 3 m , e ) none of the above
Example Output: b

Example Input: Problem: the edges of a cuboid are 4 cm , 4 cm and 6 cm . find the volume of the cuboid ? 
Options: a ) 90 , b ) 60 , c ) 96 , d ) 80 , e ) 72
Example Output: c

Example Input: Problem: in a lake , there is a patch of lily pads . every day , the patch doubles in size . it takes 48 days for the patch to cover the entire lake , how many days would it take the patch to cover half of the lake ? 
Options: a ) 36 , b ) 2 ^ 4 * 3 , c ) 24 , d ) 38 , e ) 47
Example Output:
e