Which trace element is essential for the proper functioning of the thyroid gland and helps regulate metabolic rate?

A Selenium
B Iodine ✓
C Copper
D Zinc

Explanation

Iodine is a critical trace element necessary for the synthesis of thyroid hormones, which regulate metabolic rate, growth, and development.

Source

American Thyroid Association (ATA)
Minerals and Trace Elements Endocrinology and Nutrition Thyroid Function and Iodine Easy MEDICAL Confidence: high