In how many countries does Panda Express operate?

Panda Express operates in over 10 countries, primarily in North America but also in locations such as South Korea, Canada, and Puerto Rico. This answer reflects the company's expansion strategy, which includes a significant international presence beyond just the United States. By establishing locations in multiple countries, Panda Express aims to share its unique blend of American Chinese cuisine with a diverse customer base.

The other options suggest either fewer countries or an incorrect assertion that it only operates in the United States, which does not capture the full scope of the company’s global reach. Understanding the extent of Panda Express's operations is key to recognizing its growth and international business strategy.