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: the speed of a boat in still water is 15 km / hr and the rate of current is 3 km / hr . the distance travelled downstream in 12 minutes is 
Options: a ) 1.2 km , b ) 1.8 km , c ) 2.4 km , d ) 3.6 km , e ) 1.6 km

Output: d


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 an examination , a student scores 3 marks for every correct answer and loses 2 marks for every wrong answer . if he attempts all 100 questions and secures 300 marks , the number of questions he attempts correctly , is : 
Options: a ) 150 , b ) 250 , c ) 400 , d ) 300 , e ) 100


Output: e