In a graph, a line that a curve approaches but never reaches, with distance approaching zero.

• A. Asymptote
• B. Axis
• C. Vertex
• D. Slope

Answer: (A)

Asymptotes describe lines a curve gets arbitrarily close to but never reaches. When the distance between the curve and such a line tends to zero, the graph is approaching that line as x moves toward a specific value or toward infinity, without ever touching it. This explains why that line is the correct description here. Asymptotes can be vertical, horizontal, or oblique, depending on how the curve behaves at the ends. The other terms don’t fit this idea: an axis is a fixed reference line the graph can cross or align with, a vertex is a turning point on the curve, and slope is just how steep the curve is at a point, not about approaching another line.