Goiter is caused by the abnormal functioning of :-

Options

A. Pancreas
B. Adrenals
C. Pituitary
D. Thyroid

Answer

### Step-by-Step Solution:

1. **Understanding Goiter**:
Goiter is a condition characterized by the enlargement of the thyroid gland. It is important to know which gland is responsible for this condition.

2. **Identifying the Glands**:
The question lists four glands: pancreas, adrenals, pituitary, and thyroid. We need to determine which of these glands is associated with goiter.

3. **Role of the Thyroid Gland**:
The thyroid gland is responsible for producing hormones such as T3 (Triiodothyronine) and T4 (Thyroxine). These hormones regulate metabolism and are crucial for normal growth and development.

4. **Causes of Goiter**:
Goiter is primarily caused by a deficiency in iodine, which is essential for the synthesis of T3 and T4 hormones. When there is insufficient iodine in the diet, the thyroid gland cannot produce enough of these hormones, leading to a condition known as hypothyroidism.

5. **Hypothyroidism and Goiter**:
Hypothyroidism (meaning less thyroid hormone production) causes the thyroid gland to enlarge in an attempt to produce more hormones, resulting in goiter.

6. **Conclusion**:
Therefore, the abnormal functioning that leads to goiter is specifically related to the thyroid gland.

### Final Answer:
Goiter is caused by the abnormal functioning of the **thyroid gland**.

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