This is fundamentally a "Weaken" type of question, so we need to look for answer choice that weaken the argument, "Sometime during the 1950s, rock music permanently ousted jazz from the music scene".

A．Jazz is the most important musical contribution of the linked States to world culture.

The answer is irrelevant as it does not address the argument "rock music permanently ousted jazz in the music scene." The wording is a bit extreme (most important), making this answer even more suspect.

B．Although some young people who attended nightclubs in the 1950"s did try to listen to jazz, they eventually became bored with it.

This strengthens the argument, not weaken.

C．Since the 1960" s, rock music has not only provided youths with recreation but has, as well, become a rallying point for making social statements.

This strengthens the argument, not weaken.

D．Although by 1960 jazz performances were less popular, there has since been a revival of interest in jazz among middle-class professionals.

This answer weakens the argument "Sometime during the 1950s, rock music permanently ousted jazz from the music scene", as revival of interest in jazz means the ouster of jazz from the music scene is not permanent. Answer can also be arrived through process of elimination.

E．Jazz steadily increased in popularity between the 1930"s and the 1950"s.

Irrelevant as we're talking about a period post-1950.