Which two actions may cause triggers to fire?

B. Updates to FeedItem:

Triggers can fire when FeedItem records are updated, such as posts on records or Chatter updates.

C. Cascading delete operations:

When a parent record is deleted, cascading delete operations on related child records can trigger child object triggers.

Why Not Other Options?

A: Changing a user's default division does not fire triggers.

D: Renaming or replacing a picklist entry does not fire triggers.