Question ID:PT24 S2 Q24 Passage:No mathematical proposition can be proven true by observation. It follows that it is impossible to know any mathematical proposition to be true. Stem:The conclusion follows logically if which one of the following is assumed? Correct Answer Choice:EChoice A:Only propositions that can be proven true can be known to be true. Choice B:Observation alone cannot be used to prove the truth of any proposition. Choice C:If a proposition can be proven true by observation, then it can be known to be true. Choice D:Knowing a proposition to be true is impossible only if it cannot be proven true by observation. Choice E:Knowing a proposition to be true requires proving it true by observation.