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: walking with 5 / 4 of my usual speed , i miss the bus by 5 minutes . what is my usual time ? 
Options: a ) 18 , b ) 19 , c ) 20 , d ) 22 , e ) 24

Ex Output:
c


Ex Input:
Problem: a man swims downstream 76 km and upstream 48 km taking 4 hours each time ; what is the speed of the current ? 
Options: a ) 3 kmph , b ) 1.5 kmph , c ) 3.5 kmph , d ) 6.5 kmph , e ) 7 : 3 kmph

Ex Output:
c


Ex Input:
Problem: the average wages of a worker during a fortnight comprising 15 consecutive working days was $ 90 per day . during the first 7 days , his average wages was $ 87 per day and the average wages during the last 7 days was $ 91 per day . what was his wage on the 8 th day ? 
Options: a ) $ 83 , b ) $ 90 , c ) $ 92 , d ) $ 97 , e ) $ 104

Ex Output:

e