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 square of side 70 cm in length is : 
Options: ['a ) 3600', 'b ) 2646', 'c ) 3850', 'd ) 4215', 'e ) 5205']
Example Output: c

Example Input: Problem: what should be added to 4329 so that it may become a perfect square ? 
Options: a ) 24 , b ) 25 , c ) 26 , d ) 27 , e ) 28
Example Output: d

Example Input: Problem: approximately how many cubic feet of water are needed to fill a circular swimming pool that is 80 feet across and 10 feet deep ? 
Options: a ) 10000 , b ) 50000 , c ) 80000 , d ) 85000 , e ) 90000
Example Output:
b