Final answer:
A subsidiary is the type of organizational unit necessary for each legal entity in international business to manage operations and handle accounting activities.
Step-by-step explanation:
The organizational unit that needs to be created for each legal entity to manage operations and perform accounting activities in an international business is C) Subsidiaries. Subsidiaries are individual legal entities owned by the parent company, and they can enter into contracts, own assets, and are responsible for their own taxes and liabilities. This distinct legal structure offers protection to the parent company and allows for localized management of operations, which is essential in adapting to international markets and regulatory environments.