In this task, you need to answer the given multiple-choice question on the general math. Classify your answers into 'a', 'b', 'c', 'd', and 'e'.

Example Input: Problem: company x provides bottled water to its employees in 5 liter bottles , $ 2 each . at least how many 5 l bottles must company x buy monthly , so that new contract with $ 100 fixed monthly rate and $ 1 for 10 l bottle each paid off ? ( assume that no other costs apply ) 
Options: a ) 121 , b ) 125 , c ) 132 , d ) 134 , e ) 138
Example Output: d

Example Input: Problem: in township k each property is taxed at 10 percent of its assessed value . if the assessed value of a property in township k is increased from $ 20,000 to $ 28,000 , by how much will the property tax increase ? 
Options: a ) $ 800 , b ) $ 1000 , c ) $ 600 , d ) $ 400 , e ) $ 500
Example Output: a

Example Input: Problem: the overall age of x and y is 19 year greater than the overall age of y and z . z is how many decades younger that x ? 
Options: a ) 11 , b ) 15 , c ) 12 , d ) 19 , e ) 20
Example Output:
d