Nursing classes and the NCLEX exam are a different beast than many other college courses. On exams, you're expected to not only know the answer, but the MOST right answer. This can lead to a lot of second guessing and questioning your knowledge.
To prepare for exams, there are a few things you can do to prepare for these situations. Studying for comprehension on a level of critical thinking lets you see potential answers from the lens of priority which lets you see what is MOST right of all of the choices. Studying to the point of being able to teach back the material to your study partner or tutor is a valuable way of ensuring comprehension.
Do your reading and as you progress through the material, summarize each section by writing a few key takaways. At the end of the reading, go back through the key points you have listed and try to explain them to yourself. Check for concepts that are hard for you to understand or explain. These are areas that need more attention. Finally, answer A LOT of practice questions once you feel as though you understand the material. There are many books and online resources for practice questions over all areas of nursing content. Answering questions lets you apply your knowledge to different situations and see if there are any particular areas in need of further study. Finally, find a great tutor for any areas you need more support or guidance with!
When in the exam, read carefully and try to avoid questioning your initial instinct. Its helpful to highlight or underline important pieces of the exam question while potential answers are covered up so that you can attempt to answer the question in your head before seeing your choices.