The theory which suggests that the primary cause of the elderly losing power and influence in society due to the parallel forces of industrialization and modernization is:
B. Modernization Theory
Explanation:
1. **Modernization Theory**: This theory argues that as societies modernize and industrialize, traditional values, roles, and structures change. In the context of the elderly losing power and influence, modernization leads to a shift where older individuals may find themselves marginalized or devalued in a society that increasingly values youth, productivity, and innovation.
By understanding the Modernization Theory, you can see how societal changes influenced by industrialization and modernization can impact the status and influence of the elderly within a given society.