In this task, you need to answer the given multiple-choice question on the general math. Classify your answers into 'a', 'b', 'c', 'd', and 'e'.

Problem: a company produces on an average 4000 items per month for the first 3 months . how many items it must produce on an average per month over the next 9 months , to average of 4375 items per month over the whole ? 
Options: a ) 4500 , b ) 4600 , c ) 4680 , d ) 4710 , e ) none
a

Problem: in august , a cricket team that played 120 matches won 26 % of the games it played . after a continuous winning streak , this team raised its average to 52 % . how many matches did the team win to attain this average ? 
Options: a ) 40 , b ) 52 , c ) 65 , d ) 80 , e ) 98
c

Problem: there are 8 players in a chess group , and each player plays each of the others once . given that each game is played by two players , how many total games will be played ? 
Options: a ) 10 , b ) 30 , c ) 28 , d ) 60 , e ) 90

c