Step 1: Outline the Phases of Film Production:
Filmmaking consists of Pre-production (designing, scripting, casting), Production (filming/capturing raw clips), and Post-production (refining, processing, editing).
Step 2: Mapping the Options:
Casting, script writing, and costume designing are all pre-production planning tasks. Film editing is performed after shooting concludes, classifying it strictly under post-production.
Step 3: Verification:
Editing constitutes the central processing engine of post-production. Thus, Option (C) is correct.