Which use case can be accomplished using a custom link? Choose 3 answers

The app builder needs to change the data types of new custom fields. The app builder is not able to delete and recreate any of the fields, nor modify any apex code. Which data type change will require the app builder to perform the additional steps in order to retain existing functionalities?

What should be done to provide managers access to records of which they are not the owner in a private sharing model?

The VP of Marketing wants to broadcast an e-mail to 10,000 contacts in Salesforce on a regular basis, but realizes Salesforce's mass e-mail functionality has a limitation on the number of e-mails that can be sent each day.
What action should the app builder take?

Universal Containers has created two custom objects called Seminars and Attendees. Organization-wide defaults for those objects have been set to private. Universal Containers wants to set up a new junction object between these objects. A select group of users should be able to edit records in the junction object.
Which two steps should an app builder take to configure the proper security?