Hi Abigail, so the correct answer choice here would actually be C. To get there, let's break down the argument. The flaw in the stimulus is a whole to part flaw, saying that because the whole has a characteristic (the art collection as a whole is extremely expensive), the parts must have that characteristic (each individual piece of art in the collection is extremely expensive). This is a flaw because even though the collection as a whole is extremely valuable, it could be that a few pieces in the collection are just average and medium-priced.
Option B is actually not a flaw. Unanimously means they all agreed, so if all members voted to adopt the plan, then this specific councilperson must have indeed also voted to adopt the plan.
Option C matches the whole to part flaw that the argument makes. It is saying because the paragraph as a whole is long, each individual part (the sentences) must also have the characteristic of being long. However, in reality the paragraph could be a long paragraph made of many short sentences.
Option E is incorrect because it reverses the order and is a part to whole flaw instead of a whole to part flaw. The stimulus gives the characteristic of the whole and then infers the characteristics of the parts, whereas C gives the characteristic of the parts (the atoms are elements) and then infers the characteristic of the whole (the molecule is an element).
Feel free to follow up if you have any further questions!
