According to the preface, what is the main topic of The Pluto Files?
AThe story of how Dr. Tyson became an astrophysicist
BThe history of the American Museum of Natural History
CA record of Pluto's rise and fall from planethood
DHow Dr. Tyson became interested in Pluto
AThe story of how Dr. Tyson became an astrophysicist
BThe history of the American Museum of Natural History
CA record of Pluto's rise and fall from planethood
DHow Dr. Tyson became interested in Pluto