De or het octrooiverlening?

The correct Dutch article is:

de octrooiverlening

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

How to use octrooiverlening

the octrooiverleningde octrooiverlening
this octrooiverleningdeze octrooiverlening
that octrooiverleningdie octrooiverlening
our octrooiverleningonze octrooiverlening
your octrooiverleningjouw octrooiverlening
every octrooiverleningelke octrooiverlening
which octrooiverlening?welke octrooiverlening?
a big octrooiverlening / the big octrooiverleningeen grote octrooiverlening, de grote octrooiverlening