Which drug class is focused on replacing deficient hormones in the body?

The correct answer is focused on "Hormone replacement." This drug class is specifically designed to address the deficiencies of hormones within the body, such as estrogen or testosterone, often seen in conditions like menopause or hypogonadism. By supplementing these hormones, hormone replacement therapies help restore normal physiological functions and alleviate symptoms associated with hormonal imbalances.

The other choices do not pertain to the replacement of hormones. Narcotics are primarily used for pain management and controlling severe pain but do not have a role in hormone regulation. Bronchodilators are medications that relax and open the airways in the lungs, used to treat respiratory conditions like asthma or COPD, and they do not replace hormones. Catheterics, referring to devices or drugs that facilitate catheterization, are not related to hormone replacement either. Understanding these distinctions is crucial for recognizing the specific functions and uses of different drug classes in medical practice.