De or het researchafdeling?

The correct Dutch article is:

de researchafdeling

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

How to use researchafdeling

the researchafdelingde researchafdeling
this researchafdelingdeze researchafdeling
that researchafdelingdie researchafdeling
our researchafdelingonze researchafdeling
your researchafdelingjouw researchafdeling
every researchafdelingelke researchafdeling
which researchafdeling?welke researchafdeling?
a big researchafdeling / the big researchafdelingeen grote researchafdeling, de grote researchafdeling