What role does the thyroid hormone play?

• A. Lowers blood pressure
• B. Regulates blood sugar
• C. Regulates metabolism and influences growth and development
• D. Stimulates uterine contractions

Answer: (C)

Thyroid hormone primarily regulates metabolism and influences growth and development. It does this through hormones like T3 and T4, which raise the body's metabolic rate, increase energy use, and boost heat production. This metabolic influence also supports growth processes, including bone maturation and brain development in children, and helps coordinate overall growth with other hormones.

Because the other options describe effects that aren’t the main roles of thyroid hormone—blood pressure regulation is more about cardiovascular factors, blood sugar is controlled mainly by insulin and glucagon, and uterine contractions are driven by oxytocin and prostaglandins—the statement about metabolism and development best captures what thyroid hormone does.