A patient has low levels of T3 and T4. You test for TSH and find it is elevated. You conclude that

A) Iodine deficiency is the cause of low T3 and T4 levels
B) End-organ unresponsiveness to TSH caused the low T3 and T4 levels
C) The patient has normal hypothalamic-pituitary function
D) The thyroid gland can’t concentrate iodine
E) The problem lies in organification of the thyroglobulin