The elementary sulphur is present in

Options

A. Valine , lysine and cystine
B. Tryptophan , Glutamic acid , Aspartic acid
C. Citrulline , Methionine and Glutamic acid
D. Homo-cysteine , Cystine and Methionine

Answer

To determine which option contains elementary sulfur, we need to identify the amino acids that are known to contain sulfur in their structure.

### Step-by-Step Solution:

1. **Understanding Amino Acids**: Amino acids are the building blocks of proteins and have a general structure that includes an amino group, a carboxyl group, a hydrogen atom, and a variable R group (side chain). The properties of the amino acid are determined by the R group.

2. **Identifying Sulfur-Containing Amino Acids**: Among the 20 standard amino acids, only a few contain sulfur. The primary sulfur-containing amino acids are:
- **Cysteine**: Contains a thiol (-SH) group.
- **Methionine**: Contains a thioether (-S-).
- **Homocysteine**: A derivative of methionine that also contains sulfur.

3. **Evaluating the Options**:
- **Option A**: Valine, Lysine, and Cysteine - Cysteine contains sulfur, but the other two do not.
- **Option B**: Tryptophan, Glutamic acid, and Aspartic acid - None of these contain sulfur.
- **Option C**: Citrulline, Methionine, and Glutamic acid - Methionine contains sulfur, but Citrulline and Glutamic acid do not.
- **Option D**: Homocysteine, Cysteine, and Methionine - All three of these amino acids contain sulfur.

4. **Conclusion**: The correct answer is **D**: Homocysteine, Cysteine, and Methionine, as all of these amino acids contain elementary sulfur.

### Final Answer:
**D. Homocysteine, Cysteine, and Methionine**