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'.

Example Input: Problem: the population of a bacteria colony doubles every day . if it was started 8 days ago with 3 bacteria and each bacteria lives for 12 days , how large is the colony today ? 
Options: a ) 512 , b ) 768 , c ) 13122 , d ) 2048 , e ) 4096
Example Output: c

Example Input: Problem: how many shots of 1 cm radius can be prepared from a sphere of 4 cm radius ? 
Options: a ) 33 , b ) 88 , c ) 27 , d ) 64 , e ) 99
Example Output: d

Example Input: Problem: find the length of the wire required to go 10 times round a square field containing 53824 m 2 . 
Options: ['a ) 15840', 'b ) 9280', 'c ) 2667', 'd ) 8766', 'e ) 66711']
Example Output:
b