Task: Question Answering
Input (English): Problem: a tank contains 6,500 gallons of a solution that is 5 percent sodium chloride by volume . if 2,500 gallons of water evaporate from the tank , the remaining solution will be approximately what percent sodium chloride ? 
Options: a ) 5.12 % , b ) 6.12 % , c ) 7.12 % , d ) 8.12 % , e ) 9.12 %
Output (English): d