Ribosomes are composed of

Options

A. (a) RNA only
B. (b) Proteins only
C. (c) RNA and proteins
D. (d) RNA, proteins and DNA

Explanation

### Step-by-Step Solution

1. **Understanding Ribosomes**: Ribosomes are essential cellular structures known as the "protein factories" of the cell. They play a crucial role in synthesizing proteins.

2. **Structure of Ribosomes**: Ribosomes are composed of two subunits: a large subunit and a small subunit. These subunits come together during protein synthesis.

3. **Composition of Ribosomes**: The ribosomes are made up of two main components:
- **Ribosomal RNA (rRNA)**: This is the RNA component of ribosomes, which constitutes about 62% of their structure.
- **Proteins**: These make up the remaining 38% of the ribosome's structure.

4. **Conclusion**: Given that ribosomes are made of both rRNA and proteins, the correct answer to the question "Ribosomes are composed of" is option C: RNA and proteins.

5. **Final Statement**: Therefore, ribosomes are composed of RNA and proteins.