A scientist is designing an artificial multi-cellular organism. What must they include to ensure all cells receive nutrients and remove wastes effectively?

The correct option is A transportation system for food, oxygen, and waste.

Step-by-Step Explanation:

1. Understanding Cell Size and Diffusion Limits:
In small or single-celled organisms, nutrients, oxygen, and waste products can easily diffuse across the cell membrane directly into and out of the surrounding environment because the surface area-to-volume ratio is high, and diffusion distances are very short.

2. Challenges in Multi-cellular Organisms:
As an organism increases in size and becomes multi-cellular, most of its interior cells are located far away from the external environment. Relying solely on simple diffusion across the outer surface would be too slow to supply nutrients and remove toxic wastes from deep internal cells. Therefore, direct contact of every cell with the environment is impossible.

3. Necessity of an Internal Transport System:
To overcome the limitations of diffusion over large distances, complex multi-cellular organisms require a specialized internal transportation system (such as a circulatory system). This system transports essential substances like food, water, and oxygen directly to every cell while carrying metabolic wastes away to excretory organs.

Conclusion:
Hence, to ensure all cells in an artificial multi-cellular organism receive nutrients and eliminate wastes effectively, the scientist must include a transportation system for food, oxygen, and waste.