The proteins are sent to Golgi apparatus from the rough endoplasmic reticulum for the purpose of the post-translational modification.
The Golgi apparatus or the Golgi complex packages these delivered proteins into new vesicles. This process is carried by the various enzymes which are present in the Golgi complex. When done, these proteins bud from the surface of the complex in the new vesicles which migrate to the cell membrane.
Hence, the blank can be filled with 'Golgi apparatus'.