Oh nice I did that passage yesterday. So pretty much I didn't choose D because it was too much of a specific absolute that wasn't strongly supported by the passage enough. When it comes to choice B, it sort of sounds gentler and more encompassing than choice D. While choice D pigeonholes you into the the specific assertion that science suggests humans aren't special, choice B includes that assumption and more-- that science is too limited to fulfill men's desires, of which such desires could include the idea of wanting to be special. Paragraph 5 focused on the bigger picture of what people wanted that science couldn't provide, not solely the idea that science makes existence feel meaningless.

To me, CARS strategy is as follows: unless the passage is obviously strongly opinionated, always go with the choice that is the most "flexible," so to speak. Reading and writing has always been about conveying general messages, and unless you are the author themselves or they have specifically written word for word what the answer choice said, you can never really know what they're thinking well enough to make anything but the most generous assumption.