Introduction:
A company that operates in more than one country is called a multinational company. Multinational companies are large enterprises that have a significant presence in multiple countries. They conduct business activities, such as manufacturing, trading, or providing services, in different countries around the world.

Explanation:
1. Partnership:
A partnership is a business structure where two or more individuals come together to carry out a business venture. It is not specifically related to operating in multiple countries. Partnerships can operate within a single country.

2. Corporation:
A corporation is a legal entity that is separate from its owners. It is a common form of business organization that can operate within a single country or expand its operations internationally. While corporations can be multinational, the term "corporation" does not specifically refer to companies operating in multiple countries.

3. Foreign Company:
A foreign company is a company that operates in a country other than its home country. It refers to a company that is based in one country and conducts business activities in another country. While it indicates operations in another country, it does not necessarily imply operations in multiple countries.

4. Multinational:
A multinational company, as mentioned earlier, is a large enterprise that operates in more than one country. It has subsidiaries, branches, or affiliates in multiple countries and engages in various business activities on a global scale. Multinational companies have a global presence and often have headquarters in one country while conducting operations in several others.

Conclusion:
Out of the given options, the correct answer is option 'D' - multinational company. Multinational companies are characterized by their extensive operations in multiple countries, making them distinct from partnerships, corporations, or foreign companies that may operate within a single country or have limited international activities.