Question

fff: printing your file
use the information below to answer the question.
when using a fused filament fabrication (fff) printer, the first thing to do is to get
the filament into the machine. always check the filament for temperature settings.
then feed the filament into the printer head. there are two ways for the file to get to
the printer from the computer. you can use an sd card, or you can make a direct
connection with a cable. once the printer reaches the specified temperature, it will
start printing.
while the printer is heating up, the user can use a glue stick to help the first print
stick to the print bed. you can also use masking tape or painters tape. once the
heated bed reaches 60 degrees celsius, the nozzle will start heating to 210 degrees
celsius. the printer will do a calibration so that the nozzle is at the right height
above the print bed.
the printer will do a calibration so that the nozzle is at the
right height above what?
the support structure
the print nozzle
the heat source
the print bed

Explanation:

The text explicitly states that "the printer will do a calibration so that the nozzle is at the right height above the print bed" when describing FFF printing steps.

Answer:

the print bed