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

Example Input: Problem: the area of the largest circle that can be drawn inside a rectangle with sides 18 cm by 14 cm is 
Options: ['a ) 237', 'b ) 154', 'c ) 2376', 'd ) 198', 'e ) 171']
Example Output: b

Example Input: Problem: abcd is a square . e and f are the midpoints of sides cd and bc , respectively . what is the ratio of the shaded region area to the unshaded region ? 
Options: ['a ) 1 : 1', 'b ) 2 : 1', 'c ) 3 : 1', 'd ) 5 : 3', 'e ) 8 : 3']
Example Output: d

Example Input: Problem: in may , the grounds keeper at spring lake golf club built a circular green with an area of 81 π square feet . in august , he doubled the distance from the center of the green to the edge of the green . what is the total area of the renovated green ? 
Options: a ) 100 pi , b ) 144 pi , c ) 196 pi , d ) 256 pi , e ) 324 pi
Example Output:
e