Answer:
The correct answer is option A, Archaea
Explanation:
The Eukarya domain has four kingdoms primarily - Protista, Fungi, Plantae, and Animalia.
Archaea belongs to the Archaeabacteria kingdom which constitutes of unicellular prokaryotic organsims. In the system of classification , Archaea itself constitutes a domain which is further divided into two subdivisions
a) Crenarchaeota and
b) Euryarchaeota
They are unicellular but their characteristics are very different from the bacteria, thus they constitutes an individual set of organisms.
