There are a few cardinal rules to answering exam questions. The foremost one is answer the question. You will get no reduction in score for incorrect answers, but you will absolutely get no points if you do not answer. Always answer.
Besides that, consider these points as you address questions:
Always make sure you have read the question thoroughly
Do not assume that you know the question before you have read it all through
Do not assume you know the answer before you have read the question
Make sure that you have read and understood all requirements
There is no trickery
There are no hidden requirements
Only take into account what is stated
Take into account all that is stated
Do not read other things into the question than stated
Do not make assumptions about circumstances not stated
Do not try to put your own requirements or preferences into the question
There is also a set of rules that applies to the answers in the exam that is good to keep in mind:
Only one answer is correct
Only...