Answer:
C. Doing the first solution that comes to mind.
Step-by-step explanation:
Lets break this down a bit.
A is a great problem solving step, so we can mark that off.
We can do the same for B.
However, for C, I am hesitant about this one, so I wont mark it off quite yet.
Finally, for D, it is definitely a step, so I can mark that off.
You should never do the first solution that comes to mind, since you haven't done enough brainstorming about other ideas.
Hope this helps!