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: a rhombus has area 432 sq m , one diagonal is 36 cm . find other diagonal ? 
Options: ['a ) 2400 m', 'b ) 2500 m', 'c ) 2600 m', 'd ) 2700 m', 'e ) 2900 m']

Ex Output:
a


Ex Input:
Problem: an seller earns an income of re 1 on the first day of his business . on every subsequent day , he earns an income which is just thrice of that made on the previous day . on the 20 th day of business , he earns an income of : 
Options: a ) 29 , b ) 57 , c ) 35 , d ) 20 , e ) 30

Ex Output:
b


Ex Input:
Problem: a train traveling at 72 kmph crosses a platform in 31 seconds and a man standing on the platform in 18 seconds . what is the length of the platform in meters ? 
Options: a ) 240 meters , b ) 260 meters , c ) 420 meters , d ) 600 meters , e ) can not be determined

Ex Output:

b