Answer: B. A line has one dimension because it is made up of all points that extend infinitely in either direction.
A line has a single dimension because it consists of points that extend in either direction without limit. Shapes like triangles, circles, rectangles, etc., have two dimensions and are regarded as plane shapes. A point on the other hand has no dimensions; just position. Three dimensional figures are solid shapes like spheres and cuboids. Since just one coordinate is needed to determine a point on a line, a line is just one dimensional. Lines are points drawn continuously in the same direction and it is this direction that makes them one dimensional. For example, a point “x” has zero dimensions but when this point “x” is extended continuously in one direction, it becomes a line. This line has just length and no width so it is just one dimensional.