In this task, you need to provide the correct option for a given problem from the provided options.

Ex Input:
Problem: a certain store sold pens for $ 0.35 each and pencils for $ 0.25 each . if a customer purchased both pens and pencils from the store for a total of $ 1.80 , what total number of pens and pencils did the customer purchase ? 
Options: a ) 6 , b ) 9 , c ) 10 , d ) 11 , e ) 12

Ex Output:
a


Ex Input:
Problem: at a certain organisation , the number of male members went up by 13 % in the year 2001 from year 2000 , and the number of females members went down by 6 % in the same time period . if the total membership at the organisation went up by 1.2 % from the year 2000 to 2001 , what was the ratio of male members to female members in the year 2000 ? 
Options: a ) 1 : 2 , b ) 1 : 3 , c ) 2 : 3 , d ) 3 : 5 , e ) 2 : 1

Ex Output:
d


Ex Input:
Problem: if the ratio of the sum of the first 6 terms of a g . p . to the sum of the first 3 terms of the g . p . is 343 , what is the common ratio of the g . p ? 
Options: a ) 3 , b ) 1 / 3 , c ) 2 , d ) 7 , e ) 1 / 7

Ex Output:

d