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

Ex Input:
Problem: if 20 typists can type 50 letters in 30 minutes , then how many letters will 40 typists working at the same rate complete in 1 hour ?
Options: a ) 400 , b ) 500 , c ) 350 , d ) 250 , e ) 200

Ex Output:
a

Ex Input:
Problem: a train 441 m long can cross an electric pole in 21 sec and then find the speed of the train ?
Options: a ) 88 kmph , b ) 89 kmph , c ) 76 kmph , d ) 16 kmph , e ) 18 kmph

Ex Output:
c

Ex Input:
Problem: a can give b 200 meters start and c 400 meters start in a kilometer race . how much start can b give c in a kilometer race ?
Options: a ) 111.12 , b ) 250 , c ) 111.64 , d ) 111.11 , e ) 101.12

Ex Output:
b