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

Input: Consider Input: Problem: in what ratio must tea at rs . 62 per kg be mixed with tea at rs . 72 per kg so that the mixture must be worth rs . 64.50 per kg ? 
Options: a ) 3 : 1 , b ) 2 : 1 , c ) 5 : 2 , d ) 3 : 2 , e ) 3 : 4

Output: a


Input: Consider Input: Problem: what is the greatest positive integer e such that 3 ^ e is a factor of 9 ^ 10 ? 
Options: a ) e = 5 , b ) e = 9 , c ) e = 10 , d ) e = 20 , e ) 30

Output: d


Input: Consider Input: Problem: in a group of 89 students , 36 are taking history , and 32 are taking statistics . if 59 students are taking history or statistics or both , then how many students are taking history but not statistics ? 
Options: a ) 9 , b ) 19 , c ) 27 , d ) 26 , e ) 31


Output: c