De or het randstoring?

The correct Dutch article is:

de randstoring

Rule Words ending in -ing: almost always de. See the rule

How to use randstoring

the randstoringde randstoring
this randstoringdeze randstoring
that randstoringdie randstoring
our randstoringonze randstoring
your randstoringjouw randstoring
every randstoringelke randstoring
which randstoring?welke randstoring?
a big randstoring / the big randstoringeen grote randstoring, de grote randstoring