When Pluto was cast out from the list of Planets?

When Pluto was cast out from the list of Planets?A. September 24, 2006
B. April 28, 2004
C. January 26, 2006
D. August 24, 2006

The International Astronomical Union (IAU) downgraded the status of Pluto to that of a dwarf planet because it did not meet the three criteria the IAU uses to define a full-sized planet. Essentially Pluto meets all the criteria except one- it “has not cleared its neighboring region of other objects.”
In August 2006 the International Astronomical Union (IAU) downgraded the status of Pluto to that of “dwarf planet.”