A, B and C are the disorders caused due to less secretion of thyroxine. A: This is produced in children and the symptoms are stunted growth, retarded mental development, defective teeth, protrusion of tongue and loose skin. B: It is caused in the adults, the symptoms are, low metabolic rate, loss of mental and physical vigour, increase in weight, thickening of skin, lowered heartbeat, mental dullness, etc, C: It is due to the deficiency of iodine. in our diet. Thyroid gland bulges as a swelling in the neck Identify A, B and C.

Explanation

To identify the disorders A, B, and C caused due to less secretion of thyroxine, we can analyze the symptoms and characteristics provided in the question.

### Step-by-Step Solution:

1. **Identify Disorder A:**
- The symptoms described for A include stunted growth, retarded mental development, defective teeth, protrusion of the tongue, and loose skin.
- These symptoms are characteristic of a condition that occurs in children due to a deficiency of thyroxine.
- **Conclusion:** Disorder A is **Cretinism**.
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