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'.

Example Input: Problem: the hiker walking at a constant rate of 5 miles per hour is passed by a cyclist traveling in the same direction along the same path at 20 miles per hour . the cyclist stops to wait for the hiker 5 minutes after passing her , while the hiker continues to walk at her constant rate , how many minutes must the cyclist wait until the hiker catches up ? 
Options: a ) 15 , b ) 10 , c ) 20 , d ) 30 , e ) 35
Example Output: a

Example Input: Problem: two trains of equal length are running on parallel lines in the same direction at 46 km / hr and 36 km / hr . the faster train passes the slower train in 27 seconds . what is the length of each train ( in meters ) ? 
Options: a ) 50.5 , b ) 88.5 , c ) 37.5 , d ) 55.5 , e ) 23.5
Example Output: c

Example Input: Problem: a train 300 m long is running at a speed of 99 km / hr . in what time will it pass a bridge 195 m long ? 
Options: a ) 17 , b ) 18 , c ) 19 , d ) 20 , e ) 21
Example Output:
b