The key elements of Dr$.$ Genichi Taguchi methods include the following, except:

Choice $1$ of $4$:Fitness for use by the customer on Quality Control, Quality Improvement, and Quality Planning.

Choice $2$ of $4$:The use of an outer array for factors that are uncontrollable in real life

Choice $3$ of $4$:Designing products and processes so that they are insensitive to parameters outside the design engineers$$ control.

Choice $4$ of $4$:Quality Loss function $$ measure financial loss to society resulting from poor quality