Explanation:

- Education: Enhancing skills and knowledge through education is a direct way to boost labour productivity. Educated workers are often more efficient and effective at their tasks.

- Health: Good health improves workers' physical and mental capacities, leading to higher productivity. Healthy workers are less likely to take sick leave and can often work more effectively.

- Migration: While migration can lead to reallocating labor resources, it does not directly focus on increasing individual labor productivity.

- Both (a) and (b): ? This is the correct answer. Both education and health are critical components of human capital that directly contribute to improving labor productivity.