What are use cases for Validation Rules?

A developer has completed work in the sandbox and is ready to send it to a related org.
What deployment tool should be used?

An app Builder creates an Account validation rule on the Industry field that will throw an error if the length of the field is longer than 6 characters. Another App Builder creates a workflow rule with a field update that sets the Industry field to Technology whenever the Billing City field is set to San Francisco. What will happen the next time a sales person saves an Account with a Billing City of San Francisco?

Universal Containers uses a custom object to track Site Visits. When the status of a Site Visit is changed from "In Progress" to "On Hold", the business wants the Site visit owner to be automatically assigned to an "On Hold" queue. Which capability can be used to accomplish this?

What are two reasons to create unmanaged packages? (Choose two.)