Answer: b. division of labor occurs as different workers gain expertise in tasks.
Explanation: Job specialization simply refers to the process of assigning a person or group or focusing on a certain subfield or line of expertise so that one can gain substantial knowledge in that subfield. It typically involves gaining increased expertise or specialty in a specific task or job sector.
With job specialization, a field or sector could be divided or broken down into subfields or subsections such that it fosters division of labor while also ensuring that individuals with requisite knowledge or expertise are assigned to the various subfields.