De or het massascreening?

The correct Dutch article is:

de massascreening

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

How to use massascreening

the massascreeningde massascreening
this massascreeningdeze massascreening
that massascreeningdie massascreening
our massascreeningonze massascreening
your massascreeningjouw massascreening
every massascreeningelke massascreening
which massascreening?welke massascreening?
a big massascreening / the big massascreeningeen grote massascreening, de grote massascreening