The correct answer is option 4: Thyroxin. Thyroxin is a hormone secreted by the thyroid gland, which is located in the neck. It is an important hormone that regulates the metabolism of the body.
Coming to the other options, option 1: Adrenalin, also known as epinephrine, is a hormone produced by the adrenal glands. It plays a crucial role in the fight-or-flight response by increasing heart rate and blood flow to muscles. However, it does not contain iodine.
Option 2: Progesterone is a hormone primarily produced by the ovaries in women. It is involved in the menstrual cycle and pregnancy. Progesterone does not contain iodine.
Option 3: Oxytocin is often referred to as the "love hormone" as it is released during social bonding activities such as childbirth, breastfeeding, and hugging. Although it is produced in the hypothalamus and released from the pituitary gland, it does not contain iodine.
In summary, only option 4: Thyroxin contains iodine. It is important to note that iodine is an essential element for the production of thyroid hormones.