How would they set up the Import Activity to know the name of the file?

Northern Trail Outfitters wants to set up an automation that imports a file and sends an email to the contacts when the file is dropped on the SFTP. The name of the file will change, though it will always start with thankyou_customers.

How would they set up the Import Activity to know the name of the file?
A . Set File Naming Pattern to %%AUTOMATED_FILENAME%%
B. Set File Naming Pattern to %%BASEFILENAME_FROM_TRIGGER%%
C. Filename is automatically passed to Import Activity with File Drop Automations
D. Check the ‘Use filename from Automation’ checkbox

Answer: B

Explanation:

The file naming pattern is a setting in the import activity that specifies how to identify the file to import. If the file name changes every time, but has a consistent prefix, the %%BASEFILENAME_FROM_TRIGGER%% variable can be used to match the file name based on the prefix. For example, if the file naming pattern is set to thankyou_customers_%%BASEFILENAME_FROM_TRIGGER%%.csv, it will match any file that starts with thankyou_customers_ and ends with .csv.

References: https://help.salesforce.com/articleView?id=sf.mc_as_import_file_naming_conventions.htm&type=5