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: 0.002 x 0.6 = ? 
Options: a ) 0.0012 , b ) 0.001 , c ) 0.01 , d ) 0.1 , e ) none of these

Ex Output:
a


Ex Input:
Problem: each year for 4 years , a farmer increased the number of trees in a certain orchard by 1 / 4 of the number of trees in the orchard of the preceding year . if all of the trees thrived and there were 12500 trees in the orchard at the end of 4 year period , how many trees were in the orchard at the beginning of the 4 year period . 
Options: a ) 5113 , b ) 5117 , c ) 5120 , d ) 8119 , e ) 10115

Ex Output:
c


Ex Input:
Problem: if a = 105 and a ^ 3 = 21 * 35 * 45 * b , what is the value of b ? 
Options: a ) 35 , b ) 42 , c ) 45 , d ) 49 , e ) 54

Ex Output:

a