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 500 miles into meters ? 
Options: a ) 784596 , b ) 845796 , c ) 804670 , d ) 784596 , e ) 864520

Ex Output:
c


Ex Input:
Problem: a man can row 4 kmph in still water . when the river is running at 1.8 kmph , it takes him 1 hour to row to a place and black . what is the total distance traveled by the man ? 
Options: a ) 7.13 , b ) 6.19 , c ) 4.12 , d ) 3.19 , e ) 4.21

Ex Output:
b


Ex Input:
Problem: there are two cars . one is 90 miles north of the other . simultaneously , the car to the north is driven westward at 25 miles per hour and the other car is driven eastward at 35 miles per hour . how many miles apart are the cars after 2 hours ? 
Options: a ) 120 , b ) 130 , c ) 140 , d ) 150 , e ) 160

Ex Output:

d