All animals are

a. multicellular, heterotrophic, and diploid.

b. multicellular, heterotrophic, and haploid.

c. multicellular, autotrophic, and diploid.

d. multicellular, autotrophic, and haploid.

The correct answer is option a, that is, multicellular, heterotrophic, and diploid.

Animals refer to the multicellular eukaryotic species, which forms the biological kingdom Animalia. Animals exhibit many features, which distinguish them from other living species. The animals are multicellular and eukaryotic, unlike prokaryotic bacteria, and unlike protists that are eukaryotic but unicellular.

The animals are heterotrophic, not like algae and plants that generate their own food. Almost all the animals make use of some kind of sexual reproduction. They are diploid and generate haploid gametes by the process of meiosis, the larger non-motile gametes are ova and the smaller motile gametes are spermatozoa.