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

Ex Input:
Problem: what is the square root of 121 ?
Options: a ) 11 , b ) 12 , c ) 16 , d ) 18 , e ) 25

Ex Output:
a

Ex Input:
Problem: in township k , 1 / 5 of the housing units are equipped with cable television . if 1 / 10 of the housing units , including 1 / 3 of those that are equipped with cable television , are equipped with videocassette recorders , what fraction of the housing units have neither cable television nor videocassette recorders ?
Options: a ) 23 / 30 , b ) 11 / 15 , c ) 7 / 10 , d ) 1 / 6 , e ) 2 / 15

Ex Output:
a

Ex Input:
Problem: solution a is 10 % salt and solution b is 80 % salt . if you have 30 ounces of solution a and 60 ounces of solution b , in what ratio could you mix solution a with solution b to produce 50 ounces of a 50 % salt solution ?
Options: a ) 6 : 4 , b ) 6 : 14 , c ) 3 : 4 , d ) 4 : 6 , e ) 3 : 7

Ex Output:
c