explain this if you can i struggle with Discrete and Continuous Data

Answer:
option A
{1, 2, 4, 7, 9}
Step-by-step explanation:
The domain of a function is the complete set of possible values of the independent variable. Mostly it is 'x' values.
In the figure the tail of arrow represent values of domain and head of arrow represent values of range.
So,
{1, 2, 4, 7, 9} is the domain of G(x) and {3, 5, 8} is the range