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

Ex Input:
Problem: the ratio of three numbers is 1 : 3 : 4 and the sum of their squares is 2600 . the sum of the numbers is ?
Options: a ) a ) 10 , b ) b ) 12 , c ) c ) 15 , d ) d ) 14 , e ) e ) 9

Ex Output:
a

Ex Input:
Problem: a cat leaps 6 leaps for every 5 leaps of a dog , but 2 leaps of the dog are equal to 3 leaps of the cat . what is the ratio of the speed of the cat to that of the dog ?
Options: a ) 4 : 5 , b ) 2 : 3 , c ) 4 : 1 , d ) 1 : 9 , e ) 3 : 2

Ex Output:
a

Ex Input:
Problem: sara bought both german chocolate and swiss chocolate for some cakes she was baking . the swiss chocolate cost $ 2.5 per pound , and german chocolate cost $ 1.5 per pound . if the total the she spent on chocolate was $ 30 and both types of chocolate were purchased in whole number of pounds , how many total pounds of chocolate she purchased ?
Options: a ) 7 , b ) 18 , c ) 10 , d ) 12 , e ) 11

Ex Output:
b