Question

fff: post-processing steps
use the information below to answer the question.
the most dangerous part of fused filament fabrication (fff) is removing the print
from the print bed. after the print bed has cooled, a sharp putty knife that comes with
the printer can be used. little by little, work around the print to break the connection.
it is important to use finesse and not force.
with fused filament fabrication, the minimum post - processing needed is to remove
the support structure, which usually involves sanding and cleaning the print as
well. remove the support structure by breaking it off. there will be some surface
irregularity where the support structure was in contact with the print which will
require some sanding. sandpaper has many different grit levels, ranging from 150 to
2,000. it’s important to start with a lower number to get the rough material off and
then move up as needed. another option is to use a file. once sanding is finished, an
epoxy can be applied for any irregularities or to add extra strength. the print can also
be primed and painted.
what can be added to a fused filament fabrication (fff)
print once it is done being sanded?
an epoxy
a resin
a wax coating
a support structure

Explanation:

The text mentions that after sanding, an epoxy can be applied for irregularities or to add extra strength. Resin is not mentioned in the context of what to add after sanding. Wax coating is not stated as an option. The support structure is removed, not added.

Answer:

an epoxy