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'.

Input: Consider Input: Problem: convert 500 miles to km ? 
Options: a ) 600 km , b ) 700 km , c ) 800 km , d ) 900 km , e ) 1000 km

Output: c


Input: Consider Input: Problem: in a kilometer race , a beats b by 40 meters or 10 seconds . what time does a take to complete the race ? 
Options: a ) 290 sec , b ) 190 sec , c ) 199 sec , d ) 192 sec , e ) 240 sec

Output: e


Input: Consider Input: Problem: a boat running up stram takes 6 hours to cover a certain distance , while it takes 10 hours to cover the same distance running down stream . what is the ratio between the speed of the boat and the speed of water current respectively ? 
Options: a ) 2 : 3 , b ) 5 : 6 , c ) 4 : 1 , d ) 7 : 1 , e ) 8 : 1


Output: c