A multinational corporation (MNC) is typically defined as a company that operates in multiple countries, has facilities or assets in at least one country other than its home country, and manages production or delivers services in more than one nation.
Among the options you provided, the following describes a multinational corporation:
a company that has manufacturing plants in Brazil and sends products to sell in the U.S.
This option indicates that the company operates in multiple countries (Brazil and the U.S.), which is characteristic of a multinational corporation.