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'.

Input: Consider Input: Problem: a certain number of horses and an equal number of men are going somewhere . half of the owners are on their horses ' back while the remaining ones are walking along leading their horses . if the number of legs walking on the ground is 40 , how many horses are there ? 
Options: a ) 8 , b ) 12 , c ) 14 , d ) 16 , e ) 18

Output: a


Input: Consider Input: Problem: the average of the marks of 30 students in a class is 45 . if the marks of each student are doubled , find the new average ? 
Options: a ) 85 , b ) 77 , c ) 33 , d ) 90 , e ) 75

Output: d


Input: Consider Input: Problem: by approximately what percent is x greater than 1 / 3 if ( 2 / 3 ) ( x ) = 1 ? 
Options: a ) 173 % , b ) 516 % , c ) 461 % , d ) 350 % , e ) 290 %


Output: d