A population of pigs lives on an island together with burrowing termites. Pigs that have the longest snouts tend to survive more frequently than those with shorter snouts. Over time, most of the pig population is made up of individuals that have very long snouts. This is an example of which type of selection

[content deleted] - user123802726recklesschicken

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 is lactic acid from anaerobic respiration. the acid in lactic acid is what creates sore and burning muscles. if you think about how acid burns that will give you a clue for questions like this.