Detailed Instructions: In this task, you need to answer the given multiple-choice question on the gain. Gain is the value by which to multiply the input. Classify your answers into 'a', 'b', 'c', 'd', and 'e'.
Q: Problem: sales price is $ 81 , gross profit is 170 % of cost , what is the value of gross profit ? 
Options: a ) 32 , b ) 33 , c ) 39 , d ) 40 , e ) 51
A:
e