The correct answer is option 4, Thyroid.

When the thyroid gland enlarges, it is referred to as goiter. Goiter is a condition characterized by the abnormal enlargement of the thyroid gland. The thyroid gland is located in the neck and is responsible for producing and releasing hormones that regulate metabolism, growth, and development.

A goiter can occur due to various reasons, including iodine deficiency, autoimmune diseases (such as Hashimoto`s thyroiditis or Graves` disease), or nodules or tumors in the thyroid gland. These factors can cause an increase in the size of the thyroid gland, leading to goiter.

It is important to note that goiter itself does not indicate a specific disease or condition but rather reflects an underlying problem with the thyroid gland. If a goiter is causing symptoms or is deemed to be concerning, further evaluation and possible treatment may be required.

Alert - correct answer should be: None (as there is no option matching the correct answer). The correct answer for the given question is Parathyroid. The enlargement of glands due to goiter is referring to the thyroid gland, not the parathyroid glands.