What did HTTP/1.1 add over HTTP/1.0 for connection reuse?
APersistent keep-alive connections reused across requests
BFull request multiplexing over a single shared connection
CBinary framing that replaced the plain text message format
DMandatory encryption applied to every request and response
Why this is the answer
HTTP/1.1 introduced persistent keep-alive connections so the same TCP connection serves multiple requests. True multiplexing arrived later with HTTP/2.