In a one-view drawing, the use of a center line plus the diameter symbol indicates that a part is _______?

In a one-view drawing, the presence of a center line along with the diameter symbol signifies that the part in question is cylindrical. A center line is commonly used in technical drawings to indicate symmetry and the axis of rotation for cylindrical objects. When paired with the diameter symbol, it clearly indicates that the part has a circular cross-section along its length, which is characteristic of cylindrical shapes.

Cylindrical features are defined by their circular profiles, and thus the diameter symbol communicates important information about the size of this circular section. This helps designers and engineers understand the dimensions and how the component will fit within a larger assembly. The other options denote different shapes which do not typically use the same notation in a one-view drawing, thereby reinforcing that the combination of a center line and diameter symbol is uniquely indicative of cylindrical parts.