This isn’t the main point because the author never compares the similarity of mechanisms that determine polarity to overall genetic makeup. The comparison is between mechanisms that determine polarity and those involved in features later in an organism’s developmental process.

This isn’t the main point, because the author doesn’t indicate that embryos determine polarity based on methods that differ depending on simplicity or complexity. Although different organisms have different methods, the author never suggests that simple organisms tend to use one method while more complex organisms tend to use a different method.

This best captures the main point. The entirety of P2 is designed to show that the mechanisms for establishing polarity are very different between different organisms. But, the author notes in P3 that the mechanisms for development of later features are very similar.

This isn’t the main point, because the inscription of polarity signals in the cytoplasm or p-granules are merely two of the potential polarity mechanisms. The author never suggests that all the mechanisms for polarity in all organisms are based on this cytoplasm vs. p-granule issue.

This is anti-supported. The author indicates in P1 and P2 that the mechanisms for establishing polarity are very different between different organisms.