Not necessary, because we know that even if there were some people who claimed to be tired of celebrity scandals but did not say they were unwilling to watch TV news programs, it’s still the case that “most people in our country” claimed to be tired of obsession with celebrity scandals AND to be unwilling to watch TV news programs. The argument relies on the group of people who happened to make both claims; the argument doesn’t need to assume that everyone who made the first claim also made the second claim.

Not necessary, because the conclusion merely asserts that people “often” portray themselves as they wish to be perceived, rather than as they actually are. This just requires the author to believe that many people who claimed not to watch the programs actually did watch the programs. It doesn’t require the author to think “almost everyone” who made that claim didn’t watch the programs.

Not necessary, because the author acknowledges in the conclusion that people might not have been aware that they were portraying themselves differently from how they actually were. The author said, “whether or not they are aware of it.”

Not necessary, because the conclusion merely asserts that people “often” portray themselves as they wish to be perceived, rather than as they actually are. This just requires the author to believe that many people who claimed not to watch the programs actually did watch the programs. It doesn’t require the author to think “none” of the people portrayed themselves as they actually were.

Necessary, because if it were not true — if last year NO one responding to polls wished to be perceived as unwilling to watch TV news programs — then there’s no support for the claim that people often portray themselves “as they wish to be perceived.”