Sentence 4 sets the stage by introducing the main idea that human consciousness is often regarded as an emergent property of the human brain, providing essential context for the subsequent discussion. Considering Sentences 1 and 3, Sentence 1 concludes with the statement "no single neuron holds complex information like self-awareness, hope, or pride."
Sentence 3 builds upon this idea by asserting that despite this, the collective activity of all neurons in the nervous system generates complex human emotions like fear and joy, as stated: "Nonetheless, the sum of all neurons...". Thus, it can be inferred that Sentence 3 logically follows Sentence 1. Moreover, Sentence 3 reinforces the notion that emergent properties arise from the interaction of individual components.
Finally, Sentence 2 wraps up the paragraph by explaining that while the precise mechanism of emergence in the human brain remains incompletely understood, neurobiologists concur that complex interconnections among its parts give rise to qualities specific to the whole. This sentence serves to conclude the discussion and strengthen the concept introduced in Sentence 4.
So, the correct sequence is option (A): 4132