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: the tax on a commodity is diminished by 30 % but its consumption is increased by 15 % . find the decrease percent in the revenue derived from it ? 
Options: a ) 20 % , b ) 18 % , c ) 15 % , d ) 12 % , e ) 14 %

Ex Output:
a


Ex Input:
Problem: a straight line in the xy - plane has y - intercept of 49 . on this line the x - coordinate of the point is 71 and y - coordinate is 12 then what is the slope of the line ? 
Options: a ) 0.5 , b ) 0.51 , c ) - 0.52 , d ) 0.31 , e ) - 0.49

Ex Output:
c


Ex Input:
Problem: 0.0007 ? = 0.01 
Options: a ) 70 , b ) 7 , c ) 0.7 , d ) 0.07 , e ) none of these

Ex Output:

d