De or het leaseovereenkomst?

The correct Dutch article is:

de leaseovereenkomst

How to use leaseovereenkomst

the leaseovereenkomstde leaseovereenkomst
this leaseovereenkomstdeze leaseovereenkomst
that leaseovereenkomstdie leaseovereenkomst
our leaseovereenkomstonze leaseovereenkomst
your leaseovereenkomstjouw leaseovereenkomst
every leaseovereenkomstelke leaseovereenkomst
which leaseovereenkomst?welke leaseovereenkomst?
a big leaseovereenkomst / the big leaseovereenkomsteen grote leaseovereenkomst, de grote leaseovereenkomst