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: an engineer undertakes a project to build a road 10 km long in 150 days and employs 30 men for the purpose . after 50 days , he finds only 2 km of the road has been completed . find the ( approximate ) number of extra men he must employ to finish the work in time . 
Options: a ) 22 , b ) 30 , c ) 15 , d ) 18 , e ) 20

Ex Output:
b


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: a train moves with a speed of 72 kmph . its speed in metres per second is 
Options: a ) 10.8 , b ) 18 , c ) 30 , d ) 20 , e ) none

Ex Output:

d