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: donovan and michael are racing around a circular 400 - meter track . if donovan runs each lap in 48 seconds and michael runs each lap in 40 seconds , how many laps will michael have to complete in order to pass donovan , assuming they start at the same time ? 
Options: a ) 5 , b ) 7 , c ) 8 , d ) 9 , e ) 6
Example Output: e

Example Input: Problem: calculate the circumference of a circular field whose radius is 8 centimeters . 
Options: a ) 17 π cm , b ) 18 π cm , c ) 1 π cm , d ) 16 π cm , e ) 6 π cm
Example Output: d

Example Input: Problem: the length of the bridge , which a train 120 m long and traveling at 45 km / hr can cross in 30 sec is ? 
Options: a ) 235 , b ) 240 , c ) 245 , d ) 250 , e ) 255
Example Output:
e