In this task, you need to answer the given multiple-choice question on geometry. Classify your answers into 'a', 'b', 'c', 'd', and 'e'.

Ex Input:
Problem: a box measuring 49 inches long by 21 inches wide by 14 inches deep is to be filled entirely with identical cubes . no space is to be left unfilled . what is the smallest number of cubes that can accomplish this objective ? 
Options: a ) 17 , b ) 42 , c ) 54 , d ) 108 , e ) 864

Ex Output:
b


Ex Input:
Problem: a voltage will influence current only if the circuit is : 
Options: ['a ) 2', 'b ) 7', 'c ) 6', 'd ) 889', 'e ) 1']

Ex Output:
b


Ex Input:
Problem: a semicircle is drawn with ab as its diameter . from c , a point on ab , a line perpendicular to ab is drawn , meeting the circumference of the semicircle at d . given that ac = 2 cm and cd = 6 cm , the area of the semicircle in square cm will be ? 
Options: ['a ) 30 pi', 'b ) 40 pi', 'c ) 50 pi', 'd ) 60 pi', 'e ) 70 pi']

Ex Output:

c