The simplest form in Kingdom Animalia belongs to:

Explanation

Option A: Eumetazoa is a broad grouping of animals that have true tissues and organs. It includes all animals except sponges. Option B: Bilateria is a group of animals that have bilateral symmetry, meaning that they can be divided into two equal halves along a central axis. Most animals in the kingdom Animalia are bilaterians. Option C: Protozoa is a group of single-celled organisms that are not animals. They are classified in the kingdom Protista. Option D: The simplest form in Kingdom Animalia belongs to the group known as Parazoa. They are the simplest animals in the kingdom Animalia. Parazoans are multicellular animals that lack true tissues and organs. They include the phylum Porifera, which consists of sponges. Parazoans are considered the most primitive animals within the animal kingdom and have a simpler body organization compared to other animal groups like Eumetazoa, Bilateria, and Protostomia. Option E: Protostomia is a group of animals that have a blastopore that develops into the mouth. Most animals in the kingdom Animalia are protostomes.