Which trace element plays a crucial role in the regulation of gene expression and is a component of the enzyme glutathione peroxidase?

A Selenium ✓
B Zinc
C Copper
D Manganese

Explanation

Selenium is an essential trace element that plays a critical role in antioxidant defense systems, including the enzyme glutathione peroxidase, and also regulates gene expression.

Source

Biochemistry by Stryer
Minerals and Trace Elements Trace Element Nutrition Role of Selenium Medium MEDICAL Confidence: high