Answer:
B). Its orbit is not cleared of like-sized or larger objects.
Step-by-step explanation:
As per the question, the key reason for considering Pluto as a dwarf planet instead of a planet is that 'its orbit is not cleared of like-sized or larger objects.' Pluto was official declared a dwarf planet in the August 2006 by International Astronomical Union as it failed to prove itself as a governing gravitational object in its orbit and thus, could not clear the neighborhood surrounded by its orbit. Therefore, option B is the correct answer.