Option A is the answer, Know Yourself.
There are different steps involved in making a decision like, You identify that you need to make a decision, you gather relevant information, you identify the alternatives, you choose an alternative, you make a decision and then you review the consequences.
In this whole process, it is not necessary to know yourself. You are not making an assessment of yourself. You are going to make a decision. So it is not needed to focus on yourself while making a decision.