So I've been having issues with last questions of passages. (Main Ideas)

I’ve been kinda doing them as greg said. Using the main ideas of paragraphs, however the whole thing turned out to be a mixed bag. Main ideas of paragraphs are not always applicable for this question. Here is one:

This is from toefl 6th edition practice test 3, passage 1 last question. The correct answers are A C and F. My choices were E, C and F.

After seeing the correct answers, i can see why A is an option. But there is an entire paragraph about how structures are just alike the human body and organs and it’s mostly about how pipes, skin etc are related to the human body. Here is that paragraph:

There are even 2 questions about the idea. So what am i missing here? The thing is this wasn’t the only case this happens. I take notes of main ideas of paragraphs as i read, try not to pick the repetitive answers on these questions and despite me being really careful with them (also spending the most time) i am always getting something wrong. I still get around 24-27 but honestly i wouldnt be surprised if i got this question entirely incorrect during a test even if i was sure its correct.

Okay my bad, so apparently this skeleton and skin structure is intrinsic to modern architecture not old, not “throughout history”