**Core Concept**
The Jod-Basedow effect refers to the phenomenon where individuals with endemic iodine deficiency goiter experience a surge in thyroid hormone production and subsequent hyperthyroidism following the administration of supplemental iodine. This is often seen in individuals with pre-existing thyroiditis or thyroid gland damage.

**Why the Correct Answer is Right**
When supplemental iodine is introduced to individuals with endemic iodine deficiency goiter, it can cause a rapid increase in thyroid hormone production. This is because the thyroid gland, which has been damaged or inflamed, becomes overactive and begins to produce excessive amounts of thyroid hormones. The Jod-Basedow effect is thought to occur due to the sudden increase in iodine availability, which can trigger the release of pre-formed thyroid hormones from the damaged thyroid tissue. This can lead to a range of symptoms, including weight loss, palpitations, and tremors.

**Why Each Wrong Option is Incorrect**
**Option B:** The Wolff-Chaikoff effect refers to the inhibition of thyroid hormone synthesis caused by an excess of iodine, leading to a decrease in thyroid hormone production, not an increase.

**Option C:** Thyrotoxicosis Factitia refers to the development of hyperthyroidism due to the ingestion of exogenous thyroid hormones, not the administration of supplemental iodine.

**Option D:** De Quervain's Thyroiditis is a form of thyroiditis characterized by inflammation of the thyroid gland, which can lead to a transient period of hyperthyroidism followed by hypothyroidism. However, it is not directly related to the administration of supplemental iodine.

**Clinical Pearl / High-Yield Fact**
The Jod-Basedow effect is an important consideration in areas with endemic iodine deficiency, where supplemental iodine is often used to treat goiter. It highlights the potential risks of iodine supplementation in individuals with pre-existing thyroid disease.

**✓ Correct Answer: A. Jod-Basedow effect**