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: ( 32323 + 7344 + 41330 ) - ( 317 x 91 ) = ? 
Options: a ) 54210 , b ) 54250 , c ) 52150 , d ) none of these , e ) 521500

Ex Output:
c


Ex Input:
Problem: a car ferry can hold up to 70 tons of cargo . what is the greatest number of vehicles that the ferry can carry if half the vehicles are cars with an average ( arithmetic mean ) weight of 0.75 tons and half of the vehicles are trucks with an average ( arithmetic mean ) weight of 4 tons ? 
Options: a ) 14 , b ) 20 , c ) 28 , d ) 32 , e ) 36

Ex Output:
c


Ex Input:
Problem: the average student age of a certain class which has 45 students is 14 . if one student aged 15 go to another class and the age of the class teacher is included the average changes to 14.66 . what is the age of class teacher ? 
Options: a ) 30 , b ) 35 , c ) 38 , d ) 40 , e ) 45

Ex Output:

e