Which statement is correct regarding the difference between Multisite and Multiway conferencing?

Both Multisite and Multiway require some endpoint configuration, so this distinction is not accurate and does not capture the defining requirement of an options key for Multisite.

This reverses the architectural reality - Multisite is the feature that does not require an external MCU because it runs on-box, while Multiway depends on external conferencing infrastructure.

Multiway is not limited to intrasite multipoint; it can conference participants across multiple sites by invoking an external conference bridge.

Multisite is an on-box multipoint feature built into supported Cisco TelePresence endpoints that requires a Multisite options key (license) to be purchased and activated on the endpoint itself before it can host multipoint calls natively. Without this key, the endpoint cannot serve as a multipoint host regardless of how it is configured. Multiway, by contrast, triggers an external conference bridge to handle multipoint, requiring no special license key on the endpoint.