The correct answer is B) Oil-lubricated bearings. Oil-lubricated bearings have the least friction compared to the other options. This is because the oil film between the moving surfaces reduces the direct contact and sliding friction, resulting in lower overall friction. Oil lubrication is the standard for most marine stern tube bearings as it provides effective lubrication and cooling to minimize wear and tear. In contrast, hard rubber, bronze bushings, and lignum vitae (a type of hardwood) bearings all have higher friction characteristics compared to oil-lubricated bearings. These materials rely more on the sliding friction between the surfaces, leading to higher overall friction and potential for increased wear over time.