De or het redenring?

The correct Dutch article is:

de redenring

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

This word is not in the word lists we use to double-check answers.

How to use redenring

the redenringde redenring
this redenringdeze redenring
that redenringdie redenring
our redenringonze redenring
your redenringjouw redenring
every redenringelke redenring
which redenring?welke redenring?
a big redenring / the big redenringeen grote redenring, de grote redenring