What needs to be considered before changing the field type?

The CRM Manager at Universal Containers has requested that a custom text field be converted to a picklist in order to promote better data hygiene .

What needs to be considered before changing the field type? Choose 2 answers
A . Existing list views that reference the field may be deleted.
B . Field references will be removed in Visualforce pages
C . All data should be backed up before converting a text field.
D . Changing a field type will remove existing field history.

Answer: A,C