Both plants and animals belong to the domain Eukarya. This domain includes all organisms that have cells with a nucleus enclosed within membranes, unlike bacteria and archaea, which have prokaryotic cells without a nucleus.
Here’s a brief explanation of the domains:
- Eukarya: Includes organisms with eukaryotic cells, such as plants, animals, fungi, and protists.
- Bacteria: Consists of prokaryotic organisms with simple cell structures.
- Archaea: Also consists of prokaryotic organisms, but they are distinct from bacteria and often found in extreme environments.
- Protista: This is a kingdom within the Eukarya domain, not a separate domain.
Therefore, the correct answer is a) Eukarya.