Regarding the control of thyroid secretion:

• A. free T3 and T4 exert feedback control on anterior pituitary
• B. free T3 and T4 exert feedback control on hypothalamus
• C. free T3 and T4 exert feedback control on anterior pituitary and hypothalamus
• D. free T3 and T4 do not affect day to day control of their secretion
• E. the basal metabolic rate is the most important determinant of thyroid secretion