Assertion : Last amino acid of any proteins is known as c terminal amino acid
Reason : Last amino acid of any protein posses free COOH group

Options

A. If both assertion & Reason are ture & the Reason is a correct explanation of the Assertion
B. If both Assertion & Reason ar True but Reason is not a correct explantation of the Assertion
C. If Assertion is True but the Reason is False
D. If both Assertion & Reason are false

Answer

### Step-by-Step Solution:

1. **Understanding the Assertion**:
- The assertion states that the last amino acid of any protein is known as the C-terminal amino acid.
- In protein synthesis, amino acids are linked together to form a polypeptide chain. The end of this chain that has a free carboxyl group (-COOH) is referred to as the C-terminal.

2. **Understanding the Reason**:
- The reason states that the last amino acid of any protein possesses a free carboxyl group.
- During protein synthesis, the amino acids are linked by peptide bonds, and the last amino acid in the chain has a free carboxyl group, which is characteristic of the C-terminal end.

3. **Evaluating the Truth of the Assertion**:
- The assertion is true because the last amino acid in a protein is indeed called the C-terminal amino acid.

4. **Evaluating the Truth of the Reason**:
- The reason is also true because the last amino acid does possess a free carboxyl group, which is why it is referred to as the C-terminal.

5. **Determining the Relationship**:
- The reason correctly explains the assertion. The presence of a free carboxyl group at the end of the protein chain is what defines the C-terminal amino acid.

6. **Conclusion**:
- Both the assertion and the reason are true, and the reason is a correct explanation of the assertion.

### Final Answer:
- Both the assertion and the reason are true, and the reason correctly explains the assertion.