Choose the incorrect statement(s) from the following:
A. Thyroxine — Regulation of basal metabolic rate.
B. Myxoedema — Hyposecretion of thyroid hormone.
C. Cretinism — Hypersecretion of thyroid hormone.

Correct option is A

Correct Answer: (a)
Explanation:
A (True): Thyroxine (T₄) regulates basal metabolic rate — correct.
B (True): Myxoedema is caused by hyposecretion of thyroid hormones in adults — correct.
C (False): Cretinism is due to hyposecretion of thyroid hormone during development (congenital hypothyroidism), not hypersecretion.
Information Booster:
Thyroid hormones (T₃, T₄) increase metabolic rate, heart rate, and growth processes.
Myxoedema = adult hypothyroidism; symptoms: lethargy, weight gain, puffiness.
Cretinism = congenital hypothyroidism; causes stunted growth and mental retardation.
Hyperthyroidism (e.g., Graves’ disease) produces weight loss, heat intolerance, and goitre.
Clinical distinction between hypo- and hyper- thyroid states is essential for diagnosis and treatment.