Task: Question Answering
Input (English): Problem: in a certain village , 200 litres of water are required per household per month . at this rate , if there are 10 households in the village , how long ( in months ) will 2000 litres of water last ? 
Options: a ) 1 , b ) 20 , c ) 2 , d ) 200 , e ) 2.5
Output (English): a