Which of the following is a ribosomal factory?

Options

A. Chloroplast
B. Centriole
C. Nucleolus
D. Vacuole

Explanation

To answer the question "Which of the following is a ribosomal factory?" we can follow these steps:

### Step-by-Step Solution:

1. **Understanding Ribosomes**: Ribosomes are essential cellular structures responsible for protein synthesis. They are made up of RNA and proteins.

2. **Identifying the Organelle**: The question asks for the organelle that acts as a "ribosomal factory." This means we need to find the organelle where ribosomes are produced.

3. **Options Provided**: The options given are:
- Chloroplast
- Nucleolus
- Vacuole

4. **Analyzing Each Option**:
- **Chloroplast**: This organelle is primarily involved in photosynthesis, not in the production of ribosomes.
- **Vacuole**: Vacuoles are mainly involved in storage and maintaining water balance within the cell, not in ribosome production.
- **Nucleolus**: The nucleolus is a specialized structure within the nucleus of eukaryotic cells where ribosomal RNA (rRNA) is synthesized and combined with proteins to form ribosomal subunits.

5. **Conclusion**: Based on the analysis, the nucleolus is the organelle that functions as the ribosomal factory, as it is where ribosomes are assembled.

### Final Answer:
The ribosomal factory is the **Nucleolus**.