These are regarded as "protein factories"

Options

A. Golgi complex
B. Ribosomes
C. Nucleoli
D. Microsomes

Answer

### Step-by-Step Solution:

1. **Understanding the Question**: The question asks which of the given options is regarded as "protein factories." This indicates that we are looking for an organelle or structure involved in the synthesis of proteins.

2. **Analyzing the Options**:
- **Golgi Complex**: This organelle is primarily involved in the packaging and distribution of proteins and lipids. It does not synthesize proteins.
- **Ribosome**: Ribosomes are the sites of protein synthesis in the cell. They translate messenger RNA (mRNA) into polypeptide chains, which then fold into functional proteins. This makes ribosomes the correct answer.
- **Nucleoli**: Nucleoli are involved in the production of ribosomes but do not synthesize proteins directly. They play a role in ribosome biogenesis.
- **Microbes**: While microbes can be used in research to study cellular functions, they are not considered protein factories in the context of cellular organelles.

3. **Identifying the Correct Answer**: Based on the analysis, the organelle that is regarded as the "protein factory" is the ribosome.

4. **Conclusion**: Therefore, the correct answer to the question is **ribosome**.