Final answer:
The three supra-categories of Vens that explain why siblings can be significantly different are socioeconomic status, parental treatment, and peer influences.
Step-by-step explanation:
When addressing the supra-categories of Vens that make siblings more different from each other, the best response appears to be option c) Socioeconomic status, parental treatment, peer influences. Economic statistics and measures of well-being are substantial, but they do not fully capture the enormity of differences that can exist not just between countries but also between individuals within a family. The social and environmental contexts, such as socioeconomic status, the way parents treat each child, and the influences of peer groups, all create unique experiences for each sibling. These personal experiences contribute to sibling's differentiation beyond just the biological differences.