1. Janie was having some difficulty deciding how to organize her defense for the debate competition.

2. She prepared several hypothetical arguments that her opponents might raise, and how she might reply.

3. What cognitive stage of Piaget's theory does this account best illustrate?

Formal operational stage

Explanation:

Jean Piaget develop a theory of cognitive development, according to which, children and teenagers go through different stages in the process of cognitive development. Each stage is qualitatively different from each other and as they go through stages, their thinking go through changes, from thinking based on actions to thinking based on ideas.

The last stage of his theory is called the formal operational stage and it takes place between age of 12 and up. During this stage, adolescents start to think abstractly and reason about hypothetical problems, they are also able to formulate hypothesis and test them in order to find theories and solutions to different problems based on abstract thought, they are able to consider different possibilities in an argument and to see the pros and cons of every possibility.

In this example, Janie prepared several hypothetical arguments that her opponents might raise and how she might reply. We can see that she is thinking in an abstract way and reasoning about hypothetical problems (what her opponents might say), she is considering different possibilities that might arise in the debate and see how she would respond to them. Thus, she is likely in the formal operational stage.