Problem: a survey was sent to 80 customers , 9 of whom responded . then the survey was redesigned and sent to another 63 customers , 12 of whom responded . by approximately what percent did the response rate increase from the original survey to the redesigned survey ? 
Options: a ) 2 % , b ) 5 % , c ) 14 % , d ) 28 % , e ) 69 %
e