Final answer:
The equation of the horizontal line passing through the point (2, 3) is y = 3.This equation represents a line that is parallel to the x-axis and passes through all points with a y-coordinate of 3.
Step-by-step explanation:
The equation of the horizontal line passing through the point (2, 3) has a y-coordinate that remains constant. Therefore, the correct equation is y = 3 (option D).
This equation represents a line that is parallel to the x-axis and passes through all points with a y-coordinate of 3.