Which of the following statements regarding "Six Sigma" is TRUE?

Group of answer choices

The Six Sigma program was developed by Toyota in the $1970$s$.$

Six Sigma certification is granted by the International Standards Organization $($ISO$).$

The term has two distinct meaningsone is statistical; the other is a comprehensive quality system.

Six Sigma means that about $94$ percent of a firm's output is free of defects.

The Six Sigma program is for manufacturing firms and is not applicable to services.