Which two statements are true about record types? Choose two answers

Universal Containers has a requirement that an Opportunity should have a field showing the value of its associated account's billing state. This value should not change after the Opportunity has been created. What is the recommended solution to configure this automation behavior?

Which two statements are true about an External ID field? Choose 2 answers

A new custom object is being created with a private sharing setting. The business wants to share individual records with specific people or group of people on a case by case basis. What options does the business user have to manually share individual records? Choose 3 answers

An app builder wants to create a formula field on an Account to include data from related Contacts but is unable to find the relationship in the formula editor.
What is a limitation of formulas that could be causing the issue?