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'.

Ex Input:
Problem: 5357 x 51 = ? 
Options: a ) 273232 , b ) 273243 , c ) 273247 , d ) 273250 , e ) 273207

Ex Output:
e


Ex Input:
Problem: a 100 - litre mixture of milk and water contains 36 litres of milk . ' x ' litres of this mixture is removed and replaced with an equal quantum of water . if the process is repeated once , then the concentration of the milk stands reduced at 16 % . what is the value of x ? 
Options: a ) 37.5 litres , b ) 36.67 litres , c ) 37.67 litres , d ) 36.5 litres , e ) 33.33 litres

Ex Output:
e


Ex Input:
Problem: in the xy - coordinate plane , the graph of y = - x ^ 2 + 9 intersects line l at ( p , 5 ) and ( t , 7 ) . what is the least possible value of the slope of line l ? 
Options: a ) 6 , b ) 2 , c ) - 2 , d ) 1 , e ) - 10

Ex Output:

d