How would this requirement be implemented?
Universal Shipping want to notify their Community Moderators when a member post more than one file to the community within a 15-minute window and if more than 5 files are posted to the community within 15 minutes then their account will be frozen.

A. Using a Content Rule in the Community Builder
B. Using a Rate Rule in the Community Manager
C. Using a Rate Rule in the Community Builder
D. It is not possible to moderate files in a Community
E. Using a Content Rule in the Community Manager

B. Using a Rate Rule in the Community Manager

Explanation:

Rate rules are techniques to protect your community from spammers and web bots that attack or spam your community by posting the similar message several times in a row. You can build rate rules to alert your community moderators of suspicious spammer-like activities in your community or freeze a member on the spot.

Take for example, when the universal shipping introduces a rate rule to their comunity, Community Moderators will now be alerted when a member post more than one file to the community within a 15-minute window thereby making them frooze the account accordingly.