Answer:
The correct option is D: an unending source of increased productivity
Explanation:
The effectiveness and impact of work specialization have been demonstrated by Tata, Henry Ford and other organization. They have gone a long way to show that work specialization is capable of increasing productivity and efficiency via enhancing creation of machinery and exceptional inventions. This made so many manager to see work specialization as an unending source of increased productivity in the first half of the twentieth century.