A Patient with Hypothyroidism Is Given a Prescription for Levothyroxine

A patient with hypothyroidism is given a prescription for levothyroxine (Synthroid) .When the nurse explains that levothyroxine is a synthetic form of the thyroid hormone,the patient states that he prefers to receive more natural forms of drugs.What is the nurse's best explanation to the patient?

A) The synthetic form has a stronger effect than the natural forms.
B) Levothyroxine is less expensive than the natural forms.
C) The oral form has fewer adverse effects on the gastrointestinal tract.
D) Because the half-life of levothyroxine is longer than that of the natural forms,once-a-day dosing is possible.