De or het masterthesis?

The correct Dutch article is:

de masterthesis

How to use masterthesis

the masterthesisde masterthesis
this masterthesisdeze masterthesis
that masterthesisdie masterthesis
our masterthesisonze masterthesis
your masterthesisjouw masterthesis
every masterthesiselke masterthesis
which masterthesis?welke masterthesis?
a big masterthesis / the big masterthesiseen grote masterthesis, de grote masterthesis