Final answer:
Option (4), Organisms within Kingdom Animalia are multicellular and heterotrophic, lacking a cell wall, and most reproduce sexually.
Step-by-step explanation:
Organisms within Kingdom Animalia must meet certain requirements, which include being multicellular, heterotrophic, lacking a cell wall, and most reproduce sexually. Animals are eukaryotic and require a source of food, therefore, they ingest living or dead organic matter. They do not have chloroplasts like plants and are not autotrophic; they cannot make their own food through photosynthesis.
Moreover, animals do not have a cell wall; instead, they have a structural matrix composed of proteins and other molecules. Given this information, the characteristics that apply to Kingdom Animalia from the options provided are that they are multicellular (1) and reproduce sexually (4).