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: the curved surface of a sphere is 64 π cm 2 . find its radius ? 
Options: ['a ) 8', 'b ) 3', 'c ) 4', 'd ) 9', 'e ) 7']

Ex Output:
c


Ex Input:
Problem: the sector of a circle has radius of 21 cm and central angle 180 o . find its perimeter ? 
Options: a ) 91.5 , b ) 92 , c ) 108 , d ) 94 , e ) 95

Ex Output:
c


Ex Input:
Problem: express 45 mps in kmph ? 
Options: a ) 170 , b ) 160 , c ) 162 , d ) 130 , e ) 122

Ex Output:

c


