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

Example Input: Problem: a certain store sold pens for $ 0.35 each and pencils for $ 0.25 each . if a customer purchased both pens and pencils from the store for a total of $ 1.80 , what total number of pens and pencils did the customer purchase ?
Options: a ) 6 , b ) 9 , c ) 10 , d ) 11 , e ) 12
Example Output: a

Example Input: Problem: the diluted wine contains only 8 liters of wine and the rest is water . a new mixture whose concentration is 30 % , is to be formed by replacing wine . how many liters of mixture shall be replaced with pure wine if there was initially 32 liters of water in the mixture ?
Options: a ) 2 , b ) 5 , c ) 6 , d ) 7 , e ) 8
Example Output: b

Example Input: Problem: a can contains a mixture of liquids a and b is the ratio 7 : 5 . when 3 litres of mixture are drawn off and the can is filled with b , the ratio of a and b becomes 7 : 9 . how many liter of liquid a was contained by the can initially ?
Options: a ) 7 , b ) 10 , c ) 12 , d ) 14 , e ) 16
Example Output:
a