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'.

Ex Input:
Problem: for how many integer values of n will the value of the expression 4 n + 7 be an integer greater than 1 and less than 100 ? 
Options: a ) 30 , b ) 28 , c ) 27 , d ) 25 , e ) 26

Ex Output:
d


Ex Input:
Problem: the “ a - number ” of a number x is defined as the ones digit of 2 ^ x . antony rolls a die with 6 sides labeled with the integers from 1 to 6 , each of which has an equal probability of landing face - up . he then takes 3 ^ a , where a is the a - number of the result of his die roll , and plots 3 ^ a on a number line as the point a . finally , he repeats this entire process , this time plotting the result as the point b . what is the probability that the distance between a and b is greater than the value of b ? 
Options: a ) 3 / 8 , b ) 13 / 36 , c ) 17 / 36 , d ) 19 / 36 , e ) 23 / 36

Ex Output:
b


Ex Input:
Problem: denominator of a number is 4 less than the numerator . if 6 is added to the numerator , it becomes 3 times the denominator . find the denominator . 
Options: a ) 1 , b ) 3 , c ) 5 , d ) 7 , e ) 9

Ex Output:

c