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 cyclist start on a circular track from a given point but in opposite direction with speeds of 7 m / s and 8 m / s . if the circumference of the circle is 630 meters , after what time will they meet at the starting point ? 
Options: a ) 20 sec , b ) 15 sec , c ) 42 sec , d ) 50 sec , e ) 1 min

Ex Output:
c


Ex Input:
Problem: a can do a piece of work in 18 days and b alone can do it in 10 days . b works at it for 5 days and then leaves . a alone can finish the remaining work in 
Options: a ) 5 days , b ) 6 days , c ) 7.5 days , d ) 8.5 days , e ) 9 days

Ex Output:
e


Ex Input:
Problem: a can finish a piece of work in 5 days . b can do it in 16 days . they work together for two days and then a goes away . in how many days will b finish the work ? 
Options: a ) 4 , b ) 5 , c ) 6 , d ) 7 , e ) 8

Ex Output:

c