Pour or par?

The French prepositions "pour" and "par" are often confused by non-native speakers as both translate to "for" in English. However, there are subtle differences: "pour" is used to express the purpose or benefit of an action, while "par" is often used to indicate the actor or cause of an action. This distinction can be tricky for non-natives as it requires a precise understanding of the context. Choose the correct preposition for the sentences in this exercise.