Option 1 -> Monera are prokaryotic organisms (like bacteria), not eukaryotes, and they possess cell walls.
Option 2 -> Protista are mostly unicellular eukaryotes, and many possess cell walls, not fitting the multicellular criterion.
Option 3 -> Plantae are multicellular eukaryotes but they have cell walls (cellulose) and are autotrophs, not heterotrophs.
Option 4 -> Animalia are multicellular eukaryotes that lack cell walls and obtain nutrition by consuming other organisms (heterotrophs).
Hence, Option 4: Animalia -> These organisms possess all three defining characteristics: they are multicellular, eukaryotic, lack cell walls (allowing for greater flexibility and movement), and are heterotrophic (must consume organic material for energy) -> correct