Among the following, the essential amino acid is :

Options

A. alanine
B. valine
C. proline
D. serine

Answer

To determine which of the given amino acids is essential, we can follow these steps:

### Step 1: Understand the Definition of Essential Amino Acids
Essential amino acids are those that cannot be synthesized by the body and must be obtained through diet. Non-essential amino acids can be produced by the body.

### Step 2: List the Given Amino Acids
From the question, we need to identify the essential amino acid among the following options:
1. Alanine
2. Valine
3. Proline
4. Serine

### Step 3: Classify Each Amino Acid
- **Alanine**: Non-essential amino acid (can be synthesized by the body).
- **Valine**: Essential amino acid (must be obtained from the diet).
- **Proline**: Non-essential amino acid (can be synthesized by the body).
- **Serine**: Non-essential amino acid (can be synthesized by the body).

### Step 4: Identify the Essential Amino Acid
From the classification, we see that **Valine** is the only essential amino acid among the options provided.

### Conclusion
The essential amino acid from the given options is **Valine**.

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