Answer
d.
Work Step by Step
We are looking for the association that is mismatched, which means we are looking for the association that is false.
Option a. is incorrect. Congenital hypothyroidism is a condition of a newborn infant that lacks the hormones $T_3$ and $T_4$. A deficiency in these hormones could be the result of lack of iodine during the mother's pregnancy. This association is true; therefore, this option is not the correct answer.
Option b. is incorrect. A deficiency in thyroid hormones in adults causes a condition called myxedema. Sufferers are lethargic, lose their hair, have puffy skin, and gain weight. This association is true; therefore, this option is not the correct answer.
Option c. is incorrect. Oversecretion of either $T_3$ or $T_4$ results in Graves disease. This association is true; therefore, this option is not the correct answer.
Option d. is correct. A goiter is the result of a lack of iodine in the diet, which results in the hormones $T_3$ and $T_4$ not being produced. However, the anterior pituitary continues to stimulate the thyroid, and the thyroid becomes enlarged. Calcitonin is not involved with goiters. This association is not true; therefore, this option is the correct answer.
