The public is not yet able to purchase cars powered by hydrogen fuel cells because engineers have to determine how the cars perform based on which scenario? on racetracks in real-world conditions in flooded environments on closed courses

B - In real world conditions

Makes the most sense

you did not attach the discourse, but i assume it to be the discourse on the origin and basis of inequality among men (the original titile in french is: "discours sur l'origine et les fondements de l'inégalité parmi les hommes"), also know as "second discourse". in this discourse, jean-jacques rousseau emphasizes that private property is the basis of all inequalities.

therefore, what enabled the old regime to maintain as long as it did was private property.

the answer to your question is tooth decay.