Field type conversion. Which of the following are true: (2)

An app builder wants to create a custom Sync button on Account that will call a Lightning Web Component that connects with an external system. This action should only be available If the custom Status field is set to Ready to Sync.
What should an app builder use to add this functionality to an Account record page?

Universal Containers wants users to have access to the pricing guidelines document when viewing a Contract related to an Account.
What feature should an app builder use to create easy access to the document?

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?

Universal Containers has a private sharing model for Accounts and Opportunities and uses Territory Management to grant access to records.
* Sales rep A manually shares an opportunity record with sales rep B.
* Sales rep B has access to the Account even though the Account Is NOT In sales rep B's territory.
* Sales rep C CANNOT see either record.
Based on the information given, why can sales rep B see the Account related to the Opportunity?