How can telnet be used to fingerprint a web server?

How can telnet be used to fingerprint a web server?

A. telnet webserverAddress 80

HEAD / HTTP/1.0

B. telnet webserverAddress 80

PUT / HTTP/1.0

C. telnet webserverAddress 80

HEAD /

HTTP/2.0

D. telnet webserverAddress 80

PUT / HTTP/2.0