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: convert 0.35 in to a vulgar fraction ?
Options: a ) 18 / 50 , b ) 16 / 50 , c ) 7 / 20 , d ) 19 / 50 , e ) none

Ex Output:
c

Ex Input:
Problem: it costs $ 6 for the first 1 / 4 hour to use the copier at kinkos . after the first hour it costs $ 8 per hour . if a certain customer uses the copier for 4 hours and 25 minutes , how much will it cost him ?
Options: a ) $ 23.45 , b ) $ 65.33 , c ) $ 40 , d ) $ 38.27 , e ) $ 39.33

Ex Output:
e

Ex Input:
Problem: a car started running at a speed of 30 km / hr and the speed of the car was increased by 2 km / hr at the end of every hour . find the total distance covered by the car in the first 10 hours of the journey ?
Options: a ) 288 , b ) 390 , c ) 287 , d ) 266 , e ) 161

Ex Output:
b