A major distinction between line and staff units concerns:

The correct answer is: B. Linkage of their jobs to the goals of the firm.

Line units are directly involved in the production of goods or services, while staff units provide support services to line units. Line units are responsible for achieving the goals of the firm, while staff units are responsible for providing the resources and assistance that line units need to achieve their goals.

Option A is incorrect because line and staff units can have equal access to resources.

Option C is incorrect because line and staff units can have equal linkage to the outside world.

Option D is incorrect because there is a clear distinction between line and staff units.