Sarah agrees with this: she outright states that a person forced into a task isn’t really a volunteer. However, Paul never expresses an opinion about whether forced work can also be volunteering. His focus is only on the impact of doing the work.

Paul agrees with this statement, as shown by his example of students who enjoy forced community service. Sarah, on the other hand, never gives an opinion. She says forced work isn’t volunteering, but doesn’t weigh in on whether it can be enjoyable.

Sarah disagrees with this, but Paul agrees, making it the point at issue between the two. Sarah’s conclusion is that forced service cannot foster a habit of volunteering. Paul concludes the opposite, and in doing so explicitly disagrees with Sarah on this point.

Paul agrees with this: he argues that a particular policy can foster a habit of volunteering, meaning it must be possible. However, Sarah doesn’t state an opinion. She just says that one policy can’t foster a habit of volunteering, but she might think another policy could.

Neither of the speakers says anything about the effects that a habit of volunteering would have later in life. The discussion is just about whether a certain policy could create such a habit, not what comes next.