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

Ex Input:
Problem: the ratio of toddlers to infants at a day care center is 7 to 3 . if 12 more infants join the day care to change the ratio to 7 to 5 , how many toddlers are there at this day care center ? 
Options: a ) 24 , b ) 36 , c ) 42 , d ) 72 , e ) 120

Ex Output:
c


Ex Input:
Problem: the ratio of the present ages of two friends is 2 : 3 and 6 years back , the ratio was 1 : 3 . what will be the ratio of their ages after 4 years ? 
Options: a ) 1 : 4 , b ) 3 : 4 , c ) 1 : 2 , d ) 3 : 1 , e ) 3 : 2

Ex Output:
b


Ex Input:
Problem: a girl scout was selling boxes of cookies . in a month , she sold both boxes of chocolate chip cookies ( $ 1.25 each ) and boxes of plain cookies ( $ 0.75 each ) . altogether , she sold 1,585 boxes for a combined value of $ 1 , 586.25 . how many boxes of plain cookies did she sell ? 
Options: a ) 0 , b ) 233 , c ) 500 , d ) 695 , e ) 790

Ex Output:

e