Hey there!
I attached a screenshot of some of my notes from my Hillsborough Virtual School Chemistry I, Segment 2 course. Perhaps you can find them helpful.
In a lot of (if not all, can't remember) neutralization reactions, the acid will donate a hydrogen atom to the base using single or double reaction. This is how you can tell which is the acid and which is the base.
Any given reaction that doesn't involve hydrogen is out. This rules out A, B, and C to leave you with D.
The reaction in D is a double replacement reaction that I believe is Arrhenius, since it produces a salt and water. The NaOH gives the HCl its hydrogen, meaning that NaOH is the acid and HCl is the base.
Hope this helped you out! :-)
