Final answer:
In the AP Lang exam, argumentative essays primarily use the rhetorical mode of argumentation, purposefully selected to bolster persuasive arguments.
Step-by-step explanation:
The examples used in the argumentative essays for the AP Lang exam primarily use the rhetorical mode of argumentation. This mode is integral to constructing a persuasive argument and is often used in conjunction with other strategies such as analogy, cause and effect, and comparison and contrast. However, when choosing the exact rhetorical strategy for a given piece of writing, it's essential to consider the purpose or intention behind it. For instance, if the goal is to demonstrate why one option is preferable over another, comparison and contrast would be a suitable choice.