we know that
A line parallel to the x -axis is a horizontal line.
The slope of the horizontal line is equal to zero and the equation of a horizontal line is equal to the y-coordinate of the points that go through the line
In this problem the line passes through the point [tex](2,4)[/tex]
the y-coordinate of the point is [tex]4[/tex]
so
the equation of the line is
[tex]y=4[/tex]
the answer is the option C
[tex]y=4[/tex]
