The preconscious refers to those contents that can easily reach the conscious but do not remain there. It is mainly information that we do not constantly think about, but which is necessary for the conscious to perform its functions.
These are what we have for lunch today, our address, our second name, our friends' names, our phones, some things we like - like our favorite food - recent events and so on. It is also important to remember that although it is called Preconscious, this mental level belongs to the unconscious. We can think of the preconscious as a sieve between the unconscious and the conscious, filtering the information that will pass from one level to another.
It would be B) unconscious. I know this because when you're not thinking about something it is not in your conscious mind, so it would be in your unconscious mind.
