<prompt> Please answer with one of the option in the bracket. Write reasoning in between . Write answer in between .Q:A 65-year-old woman presents to the clinic for a routine checkup. She has unintentionally lost 4.5 kg 9.9 lb in the past month but denies any other complaints. Her pulse rate is 90min, respiratory rate is 18min, temperature is 37.0C 98.6F, and blood pressure is 15070 mm Hg. An irregularly irregular rhythm is heard on auscultation of the heart. Neck examination shows a markedly enlarged thyroid with no lymphadenopathy or bruit. Laboratory tests show low serum thyroid-stimulating hormone level, high T4 level, absent thyroid-stimulating immunoglobulin, and absent anti-thyroid peroxidase antibody. Nuclear scintigraphy shows patchy uptake with multiple hot and cold areas. Which of the following is the most likely diagnosis?? A: Graves disease, B: Hashimotos thyroiditis, C: Subacute granulomatous thyroiditis, D: Toxic adenoma, E: Toxic multinodular goiter,  <response>: This is a clinical vignette describing a 65-year-old woman with unintentional weight loss, tachycardia, and enlarged thyroid on exam. Key findings include low TSH, high T4, irregularly irregular heart rhythm, and patchy thyroid uptake on nuclear scintigraphy. Graves disease is unlikely given the absent thyroid stimulating immunoglobulin. Hashimotos thyroiditis is unlikely given the absent anti-thyroid peroxidase antibody. A toxic adenoma would not cause the patchy uptake seen on nuclear scintigraphy. The patchy uptake on nuclear scintigraphy along with the enlarged thyroid and thyrotoxicosis low TSH and high T4 point to a diagnosis of toxic multinodular goiter.E: Toxic multinodular goiter 