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'.

[Q]: Problem: for a certain exam , a score of 60 was 2 standard deviations below mean and a score of 100 was 3 standard deviations above mean . what was the mean score for the exam ? 
Options: a ) 74 , b ) 76 , c ) 78 , d ) 80 , e ) 82
[A]: b


[Q]: Problem: find the value of 80641 x 9999 = m ? 
Options: a ) 807518799 , b ) 806436469 , c ) 807538799 , d ) 806329359 , e ) 817431046
[A]: d


[Q]: Problem: find the average of all prime numbers between 40 and 80 . 
Options: a ) 59.4 , b ) 56 , c ) 39.8 , d ) 44.9 , e ) none
[A]:
a