Answer: D
Explanation:
Many unicellular organisms live in bodies of water and must move around to find food. Most often, they must obtain nutrients by eating other organisms. Plant-like protists, and some types of bacteria, can make their own food through photosynthesis.
Cytoplasm maintains the internal pressure in the cell.
To view space and the foreign objects scientist may find. Also for learning purposes because it financially cost a lot to send scientists to space for research. So for research purposes.