Task: Question Answering
Input (English): Problem: along a road lie an odd number of stones placed at intervals of 10 m . these stones have to be assembled around the middle stone . a person can carry only one stone at a time . a man carried out the job starting with the stone in the middle , carrying stones in succession , thereby covering a distance of 4.8 km . then the number of stones is 
Options: a ) 35 , b ) 15 , c ) 29 , d ) 31 , e ) 29
Output (English): d