According to astrophysicist chronicles battle over pluto why did dr. tyson decide to exclude pluto from the exhibits of planets?

he thinks Pluto is a comet because it's mostly ice by volume

Explanation:

Tyson started noticing that Pluto was different from the other planets in the 1990s. At the time, other ice bodies were discovered in the outer solar system that looked similar to Pluto. Those bodies were also like Pluto in another way: They crossed orbits. Tyson says Pluto was the only planet whose orbit crossed the orbit of another planet.

d) the narrator even suggested that the white whale, moby d, was ubiquitous and present in every ocean at every moment.  

what is margin again? i’m confusion