Question

who made the official decision to downgrade pluto from a planet to a dwarf planet? a. the international astronomical union b. the museum of natural history c. the hayden planetarium d. the new york times

Explanation:

The International Astronomical Union (IAU) is the global authority for naming celestial bodies and classifying astronomical objects. In 2006, the IAU defined the criteria for a planet, and Pluto did not meet one of them (it has not cleared its orbit of other debris). The other options (Museum of Natural History, Hayden Planetarium, The New York Times) are not organizations with the authority to classify celestial objects in this official, scientific capacity.

Answer:

A. The International Astronomical Union