A sender has stream-window credit but no connection-window credit. May it send another DA…

A sender has stream-window credit but no connection-window credit. May it send another DATA frame on that stream?

1. Yes; only the stream window applies to DATA.
2. No; both the stream and connection windows need enough credit.
3. Yes, after adding an END_STREAM flag.
4. No HTTP/2 frame can be sent until the connection window grows.