Socket Mode allows a Slack application to receive Events API and interactive payloads through a WebSocket connection rather than exposing a publicly accessible HTTP Request URL. The application establishes an outbound connection to Slack, making Socket Mode particularly useful during local development, behind corporate firewalls, or in environments where inbound public HTTP traffic cannot be accepted. Slack dynamically creates the WebSocket URL through `apps.connections.open`; the URL is not a permanent endpoint. Socket Mode does not remove OAuth requirements, eliminate Block Kit, or eliminate application installation. Bot and user functionality still depends on the application's authorization model and appropriate scopes. Socket Mode simply changes how Slack delivers events and interactive payloads to the application. Therefore, B precisely identifies the architectural advantage tested by the question.