1st : Somebody can fall out and drown
2nd : The dancer can fall and hurt her leg
3rd : The fish death rate may rise
4th : The shark may eat somebody
5th : The cat or whatever that is can be eating something with a deadly sickness
I'd say B and D. Elementary school reports don't necessarily equate to knowledge of a subject (and research on the branches of government doesn't help you know <em>how</em> to govern), so A is out. C is nice, but popularity and charm do not a leader make, he might have ulterior motives to being as such, maybe taking advantage of the power? B and D show things he has done that would give him useful skills in the position.
A) one-half
You need the hyphen in between the one and half