Think about what a claim is. a claim is something that you state, even if you don't have proof. choice C is a fact, not a claim--it would be used as evidence to support a claim, but it doesn't serve as a claim itself.
i would say that B is the most appropriate claim to argue that people should be more nutritionally knowledgeable. choice D is almost a counterargument, in a sense, because it lists a flaw with food labels. choice A is a statement, but it can be proven with evidence--one could look at a food label to search for the listed items.
Trivial details are details that have little to no relation to the evidence you are supporting. Supporting details back up you evidence strongly. Trivial details will often be used to keep the audience interested (ex: A fun fact about the moon.)
Hope this helps!
