What is the most appropriate management?

A 72-year-old woman presented with a painless swelling in the front of the neck, which she had first noticed 2C3 months previously. She was otherwise well, with no symptoms of mass effect in her neck, and was not taking any medication.

On examination, her thyroid gland was moderately enlarged, and felt uniformly nodular. There was no associated lymphadenopathy. Her pulse was 78 beats per minute and regular, and there were no signs of thyrotoxicosis.

Investigations:

serum thyroid-stimulating hormone<0.01 mU/L (0.4C5.0)

serum free T424.8 pmol/L (10.0C22.0)

serum free T310.3 pmol/L (3.0C7.0)

technetium-99m scan of thyroid (20-min uptake)patchy uptake in both thyroid lobes

What is the most appropriate management?
A . carbimazole plus levothyroxine
B . partial thyroidectomy
C . radioiodine
D . repeat thyroid function tests after 6 months
E . total thyroidectomy