Answer:
The input (x) values of the relation.
Explanation:
The question is
The domain of a relation is
- the output (y) values of the relation.
- the input (x) values of the relation.
- a set of points that pair input values with output values.
- x and y values written in the form (x, y)
The domain of a relation is defined as the set of all "input" values for which the function is defined, that means some functions have restrictions in their domains like rational funcitons.
In other words, the domain is the set of x-values, that is, the set of the values for the independent variable.
Therefore, the right answer is the second choice.