While 'Request Coalescing' (Single Flight) saves backend load, what is the critical 'Failure Mode' that must be addressed during a partial backend outage?

1. A The 'Memory Leak' caused by the Gateway storing the same response 10,000 times for each user.
2. B Resource Starvation: If the single backend request hangs, the Gateway continues to accept thousands of identical requests and puts them all into a 'Wait Group'. This consumes Gateway memory and worker threads, potentially leading to an OOM crash.
3. C The Gateway might accidentally serve the same ID to two different users, leading to GDPR violations.
4. D Coalescing only works for GET requests; it has no risk for POST or PUT requests.