Answer:
distinctive competence
Explanation:
The distinctive competence denotes the various characteristic of certain business on which behalf that business perform better than its competitors. And since the business succeeds in doing those things better than its competitors, that business gains a competitive advantage over its competitors. And here, Bob's assembly is a hardware manufacturer for the doors, cabinets, windows and the bathrooms. And his assembly products are more durable and economical than its competitor's products. And thus Bob has a competitive advantage over its competitors.