Although pregnant women do not typically exhibit hyperthyroidism,maternal total T₄ levels increase during pregnancy.This benign increase in total T₄ is due to:

A)Increased synthesis of thyroid hormone-binding globulin (TBG).
B)Increased pituitary deiodinase activity.
C)Decreased placental deiodinase activity.
D)Resistance to thyroid hormone receptor signaling.
E)Decreased excretion of thyroid hormone by the kidneys.