How to write validation rule where the condition is Amount is greater than or equal 500 and custom field should not be blank. Choose 3

Which two types of metadata should be migrated between environments using change sets? (Choose two.)

A member of Universal Container's support team is assisting a sales rep in managing a top customer. The sales rep has manually shared an opportunity with the support member in hopes that the support member can update some of the technical sales fields on the record. But the support member is unable to edit the opportunity.
What is the recommended solution to provide edit access to the opportunity?

User is not the Owner of record and he has given READ/WRITE permission using Manual Sharing. However his profile only has READ permission. What will be actual permission for that record of that user.

Universal Containers wants to implement a recruiting application using an application custom and a position custom object. Each position record may have many applications associated with it.
What solution should the administrator recommend to ensure applications are retained even if the position is removed?