Complementors are defined as

• A. Competitors in other markets
• B. Regulators
• C. Companies or networks of companies that sell goods or services that are compatible with the firm's good or service.
• D. A company's customers

Answer: (C)

Complementors are firms whose offerings enhance the value of your product when used together. They create a broader ecosystem where the whole is more valuable than any single part, encouraging customers to adopt your product because it works well with the complementary goods or services. An example is a game console and the game developers—the more compatible games available, the more attractive the console becomes. That is why the correct description is those companies or networks that sell goods or services compatible with your product. The other options describe regulators, direct competitors, or customers, none of which capture the idea of added value through compatibility and joint use.