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

Example Input: Problem: the average weight of a , b , c is 45 kg . the avgwgt of a & b be 40 kg & that of b , c be 43 kg . find the wgt of b . 
Options: a ) 23 , b ) 43 , c ) 21 , d ) 31 , e ) 43
Example Output: d

Example Input: Problem: when processing flower - nectar into honey bees ' extract , a considerable amount of water gets reduced . how much flower - nectar must be processed to yield 1 kg of honey , if nectar contains 50 % water , and the honey obtained from this nectar contains 40 % water ? 
Options: a ) 1.2 kg , b ) 1.5 kg , c ) 1.7 kg , d ) 1.9 kg , e ) none of these
Example Output: a

Example Input: Problem: there are 10 teams in a certain league and each team plays each of the other teams exactly once . what is the total number of games played ? 
Options: a ) 30 , b ) 36 , c ) 42 , d ) 45 , e ) 50
Example Output:
d