Let's look at each one. Cynical (A) can mean a lot of things, but none of them are nice. It can basically mean selfish, distrustful, or mocking.
Mediagenic (B) means someone who is favorably represented by the media. In other words, it's someone who knows how to look good in front of the cameras!
Cryptic (C) describes something vague and/or mysterious.
Rhetoric (D) isn't an adjective at all: it's actually persuasive writing or speaking.
The answer should be pretty obvious here. It's B: Mediagenic.
