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

Input: Consider Input: Problem: a class has a ratio of 3 : 6 : 7 of children with red hair , blonde hair and black hair respectively . if the class has 9 kids with red hair , how many kids are there with black hair ? 
Options: a ) 7 , b ) 6 , c ) 9 , d ) 21 , e ) 63

Output: d


Input: Consider 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

Output: d


Input: Consider Input: Problem: two integers are in the ratio of 1 to 4 . if 6 is added to the smaller number , the ratio becomes 1 to 2 . find the larger integer . 
Options: a ) 4 , b ) 6 , c ) 12 , d ) 24 , e ) 30


Output: d