Answer:
Here's the answer to the best of my ability..
You're asking for what sentence is missing a hyphen and I see nothing wrong with the one sentence that doesn't have a hyphen.
But if you're asking for what sentence is using a hyphen incorrectly then option B is your answer because machine gun doesn't need a hyphen.
If you're asking which sentences are using the hyphen correctly then option's A, and C are your answer.
If you're the question you asked has no mistakes then the best answer would be option D because that's the only option without a hyphen.
Hope this helps.
A contrast or opposition between two things
Celebrities have all the elements needed to become positive role models, hence explaining why most of them inspire others. ... Celebrities' lives are easily identifiable to the public and can thus make them good role models.