Final answer:
Pluralist theory suggests that it is not rational for people with limited resources to mobilize into groups. Therefore, the correct option is D. pluralist theory
Step-by-step explanation:
The idea that it is not rational for people with limited resources to mobilize into groups comes from pluralist theory of interest group formation. Pluralist theory suggests that multiple and diverse interests compete for attention and resources, and political power is distributed among these various interests.
It argues that interest groups form as a means for individuals to engage in collective action in support of common goals. In the context of limited resources, individuals with fewer resources may face challenges in mobilizing into groups.