Product refinement as an opportunity in mature industries can be seen in all of the following examples EXCEPT$\_\_\_\_\_\_\_\_\_\_.$

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Part $1$

A$.$

availability of refrigerators with crushed ice and water through the door

B$.$

introducing a healthy menu by fast food restaurants

C$.$

selling a dollar menu items by fast food restaurants

D$.$

selling more highly concentrated detergents

E$.$

availability of motor oil formulated to operate in$$ four$-$cylinder engines