Annual Self-Classification Report
Although I'm not sure this question belongs on Stack Overflow, you more than likely need to enter 5D992 in the ECCN column. You cannot include the .c in this column, per this guidance.
If you are 5D002 and you meet the mass market criteria (distribued solely on the App Store), then enter 5D992.
See also: Self-Classification Report Generator
(I am not a lawyer.)
In most cases, as the other answer, an APP for general use, available in the store has likely ECCN 5D992 and is of type MMKT (Mass Market).
In case your app uses different and/or specific encryption technology (e.g. a VPN app, your own encryption libraries and so on) you might need a different classification.
As there are some references to this question I thought I added some links for the subject:
Apple store connect information
Be aware that you need to check yourself if all information is correct before you submit it.
Practical note: depending on your settings in Excel, your csv might not actually be using a 'comma' when you save it as a csv. Check that before you send it in!