Which of the following is a focus area of HOSA's events?

HOSA, or the Health Occupations Students of America, primarily focuses on the health science fields. This reflects the organization's mission to promote career opportunities in the health care industry and enhance the quality of health care delivery to all people. The events organized by HOSA are designed to provide students with the opportunity to develop skills and gain knowledge specifically related to various health professions, including medicine, nursing, public health, and pharmacy.

In contrast, while literary arts, environmental science, and culinary arts are fields of study and can involve important health-related aspects, they do not directly align with the core mission or focus areas of HOSA's competitive events. HOSA is dedicated to supporting and developing future health care leaders, making health science fields the clear emphasis of its programs and competitions.