The correct answer is option 4, Thyroid.

The thyroid gland is located in the neck, in the front, just below the Adam`s apple. It is a small, butterfly-shaped gland that plays a crucial role in the endocrine system. The main function of the thyroid gland is to produce thyroid hormones, primarily thyroxine (T4) and triiodothyronine (T3). These hormones regulate the body`s metabolism, growth, and development.

Option 1, Adrenal glands, are actually located on top of the kidneys, not in the neck. They produce hormones such as cortisol and adrenaline.

Option 2, Hypothalamus, is a part of the brain and not a gland. It plays a vital role in regulating various functions of the body, including body temperature, hunger, thirst, and control of the pituitary gland.

Option 3, Pituitary gland, is often referred to as the "master gland" because it controls the activity of other endocrine glands in the body. However, it is situated at the base of the brain, not in the neck.

Therefore, the correct answer to the question is option 4, Thyroid gland, as it is the only gland located in the neck.