De or het telegramwisseling?

The correct Dutch article is:

de telegramwisseling

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

How to use telegramwisseling

the telegramwisselingde telegramwisseling
this telegramwisselingdeze telegramwisseling
that telegramwisselingdie telegramwisseling
our telegramwisselingonze telegramwisseling
your telegramwisselingjouw telegramwisseling
every telegramwisselingelke telegramwisseling
which telegramwisseling?welke telegramwisseling?
a big telegramwisseling / the big telegramwisselingeen grote telegramwisseling, de grote telegramwisseling