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: a metallic sphere of radius 12 cm is melted and drawn into a wire , whose radius of cross section is 8 cm . what is the length of the wire ?
Options: a ) 16 cm , b ) 24 cm , c ) 28 cm , d ) 36 cm , e ) 39 cm

Ex Output:
d

Ex Input:
Problem: 63 men working 8 hours per day dig 30 m deep . how many extra men should be put to dig to a depth of 50 m working 6 hours per day ?
Options: a ) a ) 87 , b ) b ) 77 , c ) c ) 66 , d ) d ) 55 , e ) e ) 97

Ex Output:
b

Ex Input:
Problem: a group of men decided to do a work in 20 days , but 2 of them became absent . if the rest of the group did the work in 22 days , find the original number of men ?
Options: a ) 15 , b ) 22 , c ) 27 , d ) 29 , e ) 18

Ex Output:
b