1. **Problem Statement:** Consider a nation with three production possibilities frontiers (PPFs) showing points W, X, V, and Z. We analyze which events cause a movement from point W (on the outermost PPF) to point V (on the innermost PPF). 2. **Understanding PPFs:** A PPF shows the maximum possible output combinations of two goods given resources and technology. Moving from a point on a higher PPF (like W) to a point on a lower PPF (like V) indicates a decrease in the nation's productive capacity. 3. **Events Analysis:** - a) Reduction in patent protection period to no more than 2 years: This can reduce incentives for innovation, potentially slowing technological progress, but does not immediately reduce capital stock. - b) War destroying a substantial portion of capital stock: This directly reduces the nation's resources, shifting the PPF inward. - c) Lack of secure and enforceable property rights: This discourages investment and innovation, reducing productive capacity over time. 4. **Conclusion:** Only events that reduce productive capacity cause a movement from W to V (outer to inner PPF). Both b and c cause such reductions. **Final answer:** B. b and c only