What is the correct way to share an HttpClient across function invocations?

1. A Create a new HttpClient per invocation
2. ✓ B Use a static/singleton HttpClient or IHttpClientFactory (correct answer)
3. C Use a using block per call
4. D Store it in the function context

Shortcut: Creating a client per invocation exhausts sockets under load. A static instance or IHttpClientFactory reuses connections correctly across invocations on the same instance.