This corrects the source material. When a File Drop Automation is configured with a filename pattern trigger (for example, ' Begins With thank_you_customers ' ), the actual filename varies from run to run, so the Import Activity inside that automation cannot be hard-coded to a static name. Salesforce ' s documented mechanism is a substitution string in the File Naming Pattern field of the Import Activity that dynamically resolves to whatever file name triggered that automation run — commonly referenced as a FILENAME_FROM_TRIGGER-style token. This lets one Import Activity definition correctly ingest any file matching the trigger pattern without manual reconfiguration. There is no native ' %%AUTOMATED_FILENAME%% ' token (option A) and no ' Use filename from Automation ' checkbox (option C) in Automation Studio ' s Import Activity configuration — both are fabricated distractors. Option B is directionally sympathetic to the real behavior but is imprecise: the filename is not silently and automatically inferred with zero configuration; the consultant must explicitly set the File Naming Pattern field to the trigger-reference substitution string for the Import Activity to resolve it correctly. Consultants configuring file-drop-triggered imports should always pair the automation ' s trigger pattern with the corresponding substitution string in the Import Activity. Reference: File Drop Automations, Import Activity File Naming Pattern.