Which one of the following is proteinaceous in chemical nature?

Options

A. Thyroxine
B. FSH
C. Progesterone
D. Oxytocin is secreted by pituitary.

Explanation

To determine which of the following options is proteinaceous in chemical nature, we need to analyze the characteristics of various hormones mentioned in the question.

### Step-by-Step Solution:

1. **Understanding Proteinaceous Nature**:
- Proteinaceous substances are made up of proteins, which are polymers of amino acids. They typically have a large molecular weight and are often insoluble in lipids.

2. **Identifying Hormones**:
- We need to consider the hormones mentioned: Thyroxine, FSH (Follicle Stimulating Hormone), Progesterone, and Oxytocin.

3. **Analyzing Thyroxine**:
- Thyroxine is a hormone produced by the thyroid gland. It is derived from the amino acid tyrosine but is not classified as a protein; it is a derivative of an amino acid and is lipid-soluble.

4. **Analyzing FSH**:
- FSH is a glycoprotein hormone produced by the anterior pituitary gland. It is composed of amino acids, making it proteinaceous in nature. It has a large molecular weight and is insoluble in lipids.

5. **Analyzing Progesterone**:
- Progesterone is a steroid hormone derived from cholesterol. It is not proteinaceous; it is lipid-soluble.

6. **Analyzing Oxytocin**:
- Oxytocin is a peptide hormone composed of a small chain of amino acids. While it is made of amino acids, it is not classified as a protein in the same way that FSH is.

7. **Conclusion**:
- Among the hormones analyzed, FSH is the only one that is proteinaceous in chemical nature.

### Final Answer:
**FSH (Follicle Stimulating Hormone)** is proteinaceous in chemical nature.

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