All of the following factors play a role in determining a person's weight:
- Herdity: Genetic factors can influence a person's weight and body type.
- Activity level: The amount and intensity of physical activity a person engages in can affect weight by determining the number of calories burned.
- Body mass index (BMI): While BMI itself is a measurement that indicates weight relative to height, it is often used as an indicator related to overall weight status and health.
- Body composition: The ratio of fat to lean mass in the body can affect a person's weight and overall health.
So, the correct answer is: Herdity, Activity level, Body mass index (BMI), Body composition.