A word for something that comes to mind before other things?

There is this epistemic phenomenon X and we might take different approaches in explaining it. But one or more approaches come to mind sooner that others, perhaps because they are more well known or more received or ... .

Is there any word for such feature? Words such as "at hand", "close", "available" seem to me to have other connotations.

Solution 1:

The first word that comes to mind (wink) is obvious.

"...perhaps because they are more well known or more received or more obvious."

Definition:
easy to see, recognize, or understand.

Many synonyms of obvious would also work, for example:

• apparent
• accessible
• straightforward
• explicit

etc.

Solution 2:

My initial suggestion is initial.

existing or occurring at the beginning.

"our initial impression was favourable"