Final answer:
The most useful thyroid diagnostic test to identify an autoimmune inflammatory disease as a basis for increased levels of thyroid hormones is the Thyroid antibody test (D).
Step-by-step explanation:
The most useful thyroid diagnostic test to identify an autoimmune inflammatory disease as a basis for increased levels of thyroid hormones is the Thyroid antibody test (D).
Autoimmune inflammatory diseases, such as Hashimoto's thyroiditis, are characterized by the presence of specific antibodies that attack the thyroid gland. The Thyroid antibody test detects the presence of these antibodies and can help in the diagnosis of autoimmune thyroid diseases.
Other tests, such as the Thyroid ultrasound (A), TSH blood test (B), and Thyroid scan (C) can provide valuable information about the structure and function of the thyroid gland, but they do not directly assess autoimmune inflammation.