Empty Mail Merge Fields

In the previous version of Word, there was an option for merge fields that
would just eliminate the field if it was blank in the source data. I am
doing a mail merge with the most recent version and cannot find that option.
I am merging data from Excel and most of the address have 3 lines, but a
couple have 4 lines. Before I would just enter merge fields for all 4 lines
and the addresses that had four lines would fill up all four lines and the
addresses with 3 lines would just be three lines. Now, if there is a line
without data, it shows up as a zero. How can I that line to disappear if
there is no data to fill it?