Which of these phases will you consider for your project 'PMP Exam' ?

I´m working in Number 3. Iterative and Incremental. It´s my plan, and the exams for a metric.

I never discard a question as wrong. Even in the exam itself there will be strange questions and somehow you have to find the best answer.
A problem is formulated as it is and if allowed you might have time to rephrase, detail and reframe it. If not, you just deal with that problem and your interpretation of it.

Aaron, your steps 1-3 make up 3 sequential and overlapping phases.
Step 3 itself might be considered iterative and incremental regarding your knowledge and understanding. You should have a target and loop as long in this step 3 until you reached it by learning (target might be you reach 80% or more correct answers in mock exams).