Correct option is B
The
bolt circle is a circular center line used in engineering drawings to indicate the centers of holes that are equidistant from a common center. It is most commonly used in flange designs, wheel hub layouts, and mechanical assemblies where bolts or fasteners are evenly distributed around a central point.
Concentric:
The objects which have the same/common center is know as concentric object. Concentricity ensures uniform load distribution in mechanical assemblies.
