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'.

Input: Consider Input: Problem: the perimeter of a semi circle is 122 cm then the radius is ? 
Options: a ) 17 , b ) 28 , c ) 24 , d ) 11 , e ) 12

Output: c


Input: Consider Input: Problem: how long does a train 165 meters long running at the rate of 54 kmph take to cross a bridge 660 meters in length ? 
Options: a ) 55 sec , b ) 40 sec , c ) 45 sec , d ) 30 sec , e ) 35 sec

Output: a


Input: Consider Input: Problem: two trains of equal length , running with the speeds of 60 and 20 kmph , take 50 seconds to cross each other while they are running in the same direction . what time will they take to cross each other if they are running in opposite directions ? 
Options: a ) 12.5 , b ) 8.01 , c ) 7.5 , d ) 26 , e ) 22


Output: a