Final answer:
Mike Brown and his team did not discover Pluto; they discovered Eris, Makemake, and Haumea. Pluto was discovered in 1930 by Clyde Tombaugh and was later reclassified as a dwarf planet when other similar objects were found in the Kuiper Belt. The correct option is a.
Step-by-step explanation:
Mike Brown and his team discovered all of the following dwarf planets except Pluto. The dwarf planets discovered by Mike Brown and his team are Eris, Makemake, and Haumea.
Pluto, while being classified as a dwarf planet, was not discovered by Mike Brown and his team; it was discovered in 1930 by Clyde Tombaugh. Dwarf planets share many properties with larger planets, and some have moons.
Haumea has two moons, while Eris and Makemake each have one. Dwarf planets are part of the extensive group of trans-Neptunian objects found beyond Neptune's orbit, most notably in the Kuiper Belt.
Pluto's unique characteristics compared to the other planets in our solar system led to its reclassification as a dwarf planet by the International Astronomical Union (IAU) in 2006. The correct option is a.