Final answer:
Market Research is not a technique used for choosing a plant location, as it focuses on consumer insights rather than site evaluation, which is done using the Factor-Rating Method, Transportation Model, and Center-of-Gravity Method. Option D is correct.
Step-by-step explanation:
The technique that is not used by companies when choosing a plant location among the options provided is Market Research.
Market research is generally used for understanding consumer behavior, preferences, and market trends, rather than specifically for plant location decisions.
On the other hand, the Factor-Rating Method, Transportation Model, and Center-of-Gravity Method are all established technical approaches for evaluating potential plant sites. These methods consider various factors, such as transportation costs, which is a key factor in Weber's Location Model, and geographical positioning relative to inputs and markets, which can be analyzed using the Von Thünen's Model.