Final answer:
The Nissan plant in Mississippi represents a direct investment, where Nissan established a new manufacturing facility on its own, making it an example of greenfield investment as well.
Step-by-step explanation:
The Nissan plant in Mississippi is an example of a direct investment. In international business, direct investment refers to a situation where a company or entity establishes operations in a foreign country through the construction of new operational facilities, an acquisition, or expansion of existing facilities. Nissan's expansion into Mississippi falls under this category as it established a new operational presence in the United States by building a manufacturing plant from the ground up, which is also known as a greenfield investment. However, since the question specifically mentions the Nissan plant without reference to any joint or collaborative effort, it is most accurately categorized as a direct investment.