The division of labour occurs in:

Correct option is D

Correct Answer:D. Both unicellular and multicellular organisms

Explanation:
Division of labour refers to the specialization of tasks to improve efficiency and functioning. This occurs in both unicellular and multicellular organisms but in different ways:

In Unicellular Organisms:

• Cellular Components: In unicellular organisms like bacteria and amoeba, various organelles perform specialized functions to sustain life.
• Example: Mitochondria for energy production, ribosomes for protein synthesis.
• Functional Efficiency: Even a single cell divides its activities among different organelles to ensure survival and reproduction.

In Multicellular Organisms:

• Specialized Cells: In multicellular organisms, cells specialize to perform specific functions, forming tissues, organs, and systems.
• Example: Nerve cells for transmitting signals, red blood cells for oxygen transport.
• Complex Systems: Organs work together in systems (e.g., the circulatory system) to achieve complex tasks efficiently.