Your API uses a 'Fixed Window' rate limiter (100 req/min). A client sends 100 requests at 12:00:59 and 100 more at 12:01:01. What happens?

1. A The first batch is rejected because the window resets on calendar minutes, but the second batch succeeds as it falls into a new processing window.
2. B The rate limiter blocks the second batch entirely, as the client's global request count exceeded 100 in a rolling 60-second window across all periods.
3. C Both batches succeed because they reside in different fixed calendar windows, but the server experiences a burst of 200 requests within a 2-second period.
4. D The requests are automatically queued by the API Gateway and processed at a constant rate of 1.6 requests per second until the total burst is cleared.