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

Ex Input:
Problem: the marks obtained by polly and sandy are in the ratio 5 : 6 and those obtained by sandy and willy are in the ratio of 9 : 7 . the marks obtained by polly and willy are in the ratio of . . . ? 
Options: a ) 9 : 8 , b ) 11 : 10 , c ) 13 : 12 , d ) 15 : 14 , e ) 17 : 16

Ex Output:
d


Ex Input:
Problem: what is the greatest value of x such that 4 ^ x is a factor of 21 ! ? 
Options: a ) 5 , b ) 6 , c ) 3 , d ) 2 , e ) 4

Ex Output:
b


Ex Input:
Problem: in two alloys , copper and tin are related in the ratios of 4 : 1 and 1 : 3 . 10 kg of ist alloy , 16 kg of 2 nd alloy and some pure copper melted together . an alloy obtained in which the ratio of copper and tin was 3 : 2 . find the weight of the new alloy . 
Options: a ) 34 kg , b ) 35 kg , c ) 36 kg , d ) 30 kg , e ) 32 kg

Ex Output:

b