Final answer:
Ninth graders are at risk of health challenges due to lack of awareness, transition difficulties, and academic pressure.
Step-by-step explanation:
Ninth graders face specific health challenges due to several factors. They may experience a lack of awareness about health issues and how to deal with them, transition difficulties because they are at a stage of moving from middle school to high school, and academic pressure, which can lead to increased stress and related health problems. It is a combination of these factors that places ninth graders at risk of specific health challenges.