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'.

Ex Input:
Problem: what is the minimum number of square tiles required to tile a floor of length 5 metres 78 cm and width 3 metres 74 cm ? 
Options: a ) 187 , b ) 180 , c ) 190 , d ) 195 , e ) 197

Ex Output:
a


Ex Input:
Problem: 9 spheres of the same size are made from melting a solid cylinder of 16 cm diameter and 12 cm height . what is the diameter of each sphere ? 
Options: ['a ) 4 cm', 'b ) 6 cm', 'c ) 8 cm', 'd ) 10 cm', 'e ) 12 cm']

Ex Output:
c


Ex Input:
Problem: 20 workers can finish a work in 30 days . after how many days should 5 workers leave the job so the work is completed in 35 days ? 
Options: a ) 7 , b ) 6 , c ) 15 , d ) 4 , e ) 3

Ex Output:

c