Fe(NO3)2 is iron(II) nitrate. To determine the parent acid, we need to understand the following:

* Nitrates are salts formed by the reaction of nitric acid (HNO3) with a base.

* Iron(II) indicates that the iron ion has a +2 charge (Fe²⁺).

Therefore, the parent acid of Fe(NO3)2 is nitric acid (HNO3).