Question: In a V2X Application Enabler (VAE) Services context, what is the requirement for supporting HTTP/1.1 over TLS, and what is the approach for utilizing HTTP/2?
Option 1: Support for both HTTP/1.1 over TLS and HTTP/2 is mandatory, with direct negotiation for HTTP/2.
Option 2: Support for HTTP/1.1 over TLS is recommended, while support for HTTP/2 is mandatory without needing an upgrade mechanism.
Option 3: Support for HTTP/1.1 over TLS is optional, and HTTP/2 can be used directly without any negotiation process.
Option 4: Support for HTTP/1.1 over TLS is mandatory, while support for HTTP/2 is recommended, requiring the use of an HTTP upgrade mechanism for negotiation.
Explanation: This correct answer reflects a nuanced understanding of the specifications. Mandatory support for HTTP/1.1 over TLS ensures baseline compatibility and security. Meanwhile, recommended (not mandatory) support for HTTP/2, via an HTTP upgrade mechanism, allows for more efficient communication when both parties support it, without disrupting basic functionality, balancing backward compatibility with potential enhanced performance.