First thing we have to take notice that this graph is discreet, meaning it can only take certain numbers .
so height represent discreet data ; at a certain age, we can measure height of a person .
whereas distance , temperature and number of hours are continuos data as the can take ANY numbers
Answers :
1. option 2 is correct , this is the height ( in feet) of a student is a function of the student age .
2. The domain of the function is discreet, because the value of x must be 0,4 and 8 ( extra notes : we cannot take a statement that says ANY number , because we are working with discreet data that doesnt take ANY number, so the best option is 0,4, 8)