Colorado Cosmetology Written Practice Exam 2026 - Free Cosmetology Practice Questions and Study Guide

Exposure to ultra violet light (option C) can help kill bacteria on the skin. Sunlight (option B) itself does not have the same bacteria-killing properties as ultra violet light. Antibiotics (option A) are typically prescribed to be taken internally, and, if used externally, may cause other issues such as dryness and irritation. Water (option D) does not necessarily kill bacteria on the skin, but can help to wash away dirt and oils that bacteria thrive on.