Final answer:
Foreign direct investment offers the most control and highest potential return for a company entering a foreign market.
Step-by-step explanation:
The mode of foreign market entry that offers the most control and the highest potential return for a company is foreign direct investment. With foreign direct investment, the investor purchases more than ten percent of a company and typically assumes some managerial responsibility, which allows for greater control and influence over operations. Additionally, foreign direct investment often has a more long-run focus compared to other modes of entry.