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'.

Input: Consider Input: Problem: the mean of 50 observations was 36 . it was found later that an observation 48 was wrongly taken as 23 . the corrected new mean is : 
Options: a ) 36.5 , b ) 35 , c ) 34 , d ) 33 , e ) 32.5

Output: a


Input: Consider Input: Problem: 998 x 998 = ? 
Options: a ) 996000 , b ) 1000000 , c ) 996004 , d ) 4000 , e ) 996008

Output: c


Input: Consider Input: Problem: joan took out a mortgage from hel local bank . each monthly mortgage payment she makes must be triple the amount of the previous month ' s payment . if her first payment is $ 100 , and the total amount she must pay back is $ 914800 , how many months will it take joan to pay back her mortgage ? 
Options: a ) 6 , b ) 8 , c ) 10 , d ) 9 , e ) 13


Output: d