Nate Is Gaining Weight, Is Often Tired, and Feels Cold

Nate is gaining weight, is often tired, and feels cold. His thyroid hormone level is high as is the level of TSH. Nate also has a goiter. Which of these diagnoses is the most likely for Nate's condition?

A) defective thyroid hormone receptors in his body cells
B) insufficient iodine in his diet
C) defective receptors for thyroid hormone control by the anterior pituitary
D) too much iodine in the diet