Final answer:
The point (5, 3) lies in the first quadrant (I) of the Cartesian coordinate system, where both x and y coordinates are positive.
Step-by-step explanation:
The point (5, 3) lies in the first quadrant of a Cartesian coordinate system. This quadrant is defined by positive x-values and positive y-values. Since 5 is positive and lies horizontally to the right side of the coordinate system, and 3 is positive and lies vertically upward in the coordinate system, the point (5, 3) is in the region where both coordinates are positive, which is the first quadrant, or Quadrant I.