Practitioner requires you not only to understand the base theory of PRINCE2 but how it can be used and tailored in different circumstances.
The PRINCE2 Practitioner exam is always based on a case study (Scenario). Take note of what is to be produced by the project or stage and what is not, otherwise, you may answer incorrectly.
TIP: Always use a process of elimination technique first and foremost, and always answer it from a PRINCE2 perspective and not what is happening at your workplace.
Like all examinations, PRINCE2 needs you to have a clear understanding of the topic and syllabus, so reference the Practitioner Exam Syllabus.