Final answer:
The primary incentive problem of an economic system is how to get people to work hard and innovate, as it is central to resource allocation, scarcity, and encouraging economic growth.
Step-by-step explanation:
The primary incentive problem of an economic system is b) how to get people to work hard and to innovate. This is because economic systems are fundamentally concerned with resource allocation and scarcity. Each system needs to address how to encourage individuals and organizations to use their limited resources in the most productive way possible. Providing the right incentives is crucial for promoting hard work and innovation, which are essential for economic growth and development. The other options, such as caring for one's neighbor, making efficient use of resources, and meeting consumer demand, while important, are secondary concerns that arise from the primary incentive to work hard and innovate.