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: two diagonals of a rhombus are 72 cm and 30 cm respectively . what is its perimeter ? 
Options: ['a ) 136 cm', 'b ) 156 cm', 'c ) 144 cm', 'd ) 121 cm', 'e ) 126 cm']

Output: b


Input: Consider Input: Problem: in what time will a train 140 meters long cross an electric pole , if its speed is 210 km / hr 
Options: a ) 5 seconds , b ) 4.5 seconds , c ) 3 seconds , d ) 2.4 seconds , e ) none of these

Output: d


Input: Consider Input: Problem: a and b undertake to do a piece of work for $ 600 . a alone can do it in 6 days while b alone can do it in 8 days . with the help of c , they finish it in 3 days . find the share of a ? 
Options: a ) $ 100 , b ) $ 150 , c ) $ 300 , d ) $ 250 , e ) $ 350


Output: c