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: two trains 120 m and 160 m long run at the speed of 60 km / hr and 40 km / hr respectively in opposite directions on parallel tracks . the time which they take to cross each other is ?
Options: a ) 10.9 , b ) 10.7 , c ) 10.3 , d ) 10.08 , e ) 10.2

Ex Output:
d

Ex Input:
Problem: two passenger trains start at the same hour in the day from two different stations and move towards each other at the rate of 12 kmph and 21 kmph respectively . when they meet , it is found that one train has traveled 60 km more than the other one . the distance between the two stations is ?
Options: a ) 477 , b ) 396 , c ) 279 , d ) 276 , e ) 291

Ex Output:
b

Ex Input:
Problem: harry started a 7 - mile hike with a full 11 - cup canteen of water and finished the hike in 3 hours with 2 cup of water remaining in the canteen . if the canteen leaked at the rate of 1 cup per hour and harry drank 3 cups of water during the last mile , how many cups did he drink per mile during the first 6 miles of the hike ?
Options: a ) 2 / 6 , b ) 3 / 6 , c ) 4 / 6 , d ) 6 / 4 , e ) 5 / 6

Ex Output:
b