A. It has negligible mass
B. It has not nearly round shaped
C. It does not have always same neighbouring planet
D. All of the above

Submitted by: Bello Ktk

A dwarf planet is, “a celestial body orbiting a star that is massive enough to be rounded by its own gravity but has not cleared its neighboring region of planetesimals and is not a satellite. More explicitly, it has to have sufficient mass to overcome its compressive strength and achieve.
The above definition was adopted by IAU 2006.

• The dwarf planet is a celestial body that is orbiting around the sun and a mass to assume a nearly round shape.
• It has not cleared the neighborhood space around it and not comes in satellite category. It is far from other planets. This the major difference between a planet and a dwarf planet.
• These criteria are fulfilled by Pluto.
• Pluto prior to this adaptation was considered as ninth planet of Solar system. In 2006, its status changed to dwarf planet.
• Pluto is an icy dwarf planet inside the Kupier belt. It was discovered in 1930 and considered then as part of solar system.
  So, it does not have always the same neighbouring planet is the correct option.

There are currently five dwarf planets: Pluto, Eris, Makemake, Haumea, and Ceres.