Question: What happens to an incoming page from an external system entity when the USAT Interpreter is in its idle state?
Option 1: The page is rendered immediately, triggering a proactive session.
Option 2: The page is queued until the USAT Interpreter leaves the idle state.
Option 3: The protocol layer discards the page if it's an operational pull message.
Option 4: The USAT Interpreter switches to wait state before processing the page.
Explanation: According to the activation rules for the USAT Interpreter, when in its idle state, the protocol layer discards pages from external system entities received as operational pull messages, ensuring state integrity until a valid activation method is invoked.