De or het interim-oplossing?

The correct Dutch article is:

de interim-oplossing

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

How to use interim-oplossing

the interim-oplossingde interim-oplossing
this interim-oplossingdeze interim-oplossing
that interim-oplossingdie interim-oplossing
our interim-oplossingonze interim-oplossing
your interim-oplossingjouw interim-oplossing
every interim-oplossingelke interim-oplossing
which interim-oplossing?welke interim-oplossing?
a big interim-oplossing / the big interim-oplossingeen grote interim-oplossing, de grote interim-oplossing