Which type of line features an arrowhead at only one end?

The correct answer is associated with a break line. A break line is used in technical drawings to indicate that a part has been shortened or to show a break in an object. The arrowhead at one end signifies the start of the break, while the line continues on the other end to represent where the object would extend if it were not broken.

In comparisons with the other types of lines: extension lines are used to extend the dimension lines from the object so they can be read easily, and they do not have arrowheads at either end. Dimension lines, which also facilitate the measurement of the object, typically have arrowheads at both ends. Center lines, used to denote the axis of symmetry in objects, incorporate long and short dashes but do not feature arrowheads. Therefore, break lines are distinct in that they uniquely have an arrowhead at only one end to indicate a disruption or omission in the drawing.