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: five bells commence tolling together and toll at intervals of 2 , 4 , 6 , 8 10 seconds respectively . in 20 minutes , how many times do they toll together ? 
Options: a ) 11 , b ) 10 , c ) 15 , d ) 16 , e ) 17
Example Output: a

Example Input: Problem: a bullet train 200 m long is running with a speed of 69 kmph . in what time will it pass a man who is running at 3 kmph in the direction opposite to that in which the bullet train is going ? 
Options: a ) 10 sec , b ) 15 sec , c ) 12 sec , d ) 11 sec , e ) 16 sec
Example Output: a

Example Input: Problem: a rectangular grassy plot 110 m . by 65 m has a gravel path 2.5 m wide all round it on the inside . find the cost of gravelling the path at 50 paise per sq . metre 
Options: a ) s 425 , b ) s 780 , c ) s 880 , d ) s 480 , e ) s 980
Example Output:
a