What should the administrator implement to help ensure consistent formatting?

Cloud Kicks wants its sales reps to always use the same full zip code format with a hyphen where applicable.

What should the administrator implement to help ensure consistent formatting?
A . Edit the standard field length to five characters.
B . Add a quick create function for the sales reps to use.
C . Create a REGEX function to use in a validation rule on the field.
D . Add a help text instructing the sales rep on how to enter this field.

Answer: C