De or het definitiestudie?

The correct Dutch article is:

de definitiestudie

How to use definitiestudie

the definitiestudiede definitiestudie
this definitiestudiedeze definitiestudie
that definitiestudiedie definitiestudie
our definitiestudieonze definitiestudie
your definitiestudiejouw definitiestudie
every definitiestudieelke definitiestudie
which definitiestudie?welke definitiestudie?
a big definitiestudie / the big definitiestudieeen grote definitiestudie, de grote definitiestudie