In Salesforce, triggers are executed in response to specific database events on standard objects (such as Account or Contact) and custom objects. The following actions can cause triggers to fire:
Option A: Cascading delete operations
Reference:
"Deleting a parent record in a master-detail relationship deletes all the detail records. This deletion can fire any triggers on those detail records."
- Salesforce Developer Guide: Triggers and Order of Execution
Option C: Updates to FeedItem
"You can write triggers for certain standard objects, including FeedItem."
- Salesforce Developer Guide: Triggers
Why Other Options Are Incorrect:
Option B: Changing a user's default division does not fire triggers because it does not perform DML operations on records that would invoke triggers.
Option D: Renaming or replacing a picklist entry changes metadata and does not perform DML operations on records, so triggers are not fired.