Quadrants are defined by which lines?

• A. Horizontal and vertical lines intersecting at the waistline
• B. Diagonal lines crossing the torso
• C. Vertical lines through the shoulders
• D. Circles centered at the navel

Answer: (A)

Quadrants are defined by two perpendicular lines that intersect at a central point on the torso, typically at the waistline. This setup divides the area into four regions: upper left, upper right, lower left, and lower right, providing a stable, standard way to describe locations quickly and consistently. Diagonal lines wouldn’t produce four equal sections, a single vertical line through the shoulders wouldn’t cross at the waist to form the traditional four quadrants, and circles centered at the navel don’t create quadrants at all but concentric rings.