Quality control methods were originally designed with three$-$sigma limits$.$ Many companies have now adopted the six sigma philosophy. The difference in terms of number of defects is quite dramatic. Three sigma quality implies an average of defects per million, while six$-$sigma quality implies an average of defects per million?

a$.3\%,6\%$

b$.2,600,3\mathrm{.}4$

c$.3\mathrm{.}4,2,600$