De or het pensionviering?

The correct Dutch article is:

de pensionviering

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

This word is not in the word lists we use to double-check answers.

How to use pensionviering

the pensionvieringde pensionviering
this pensionvieringdeze pensionviering
that pensionvieringdie pensionviering
our pensionvieringonze pensionviering
your pensionvieringjouw pensionviering
every pensionvieringelke pensionviering
which pensionviering?welke pensionviering?
a big pensionviering / the big pensionvieringeen grote pensionviering, de grote pensionviering