The VP of Finance wants to ensure that once an opportunity is closed, it cannot be modified by any user.
How can an administrator meet this requirement?

Which mechanism is used to set the number of days (integer) after which Resolved Incidents are automatically closed?

Can a group have a parent group?

The "Assigned to me" button will validate if the current user is a member of the Assignment Group.

A developer created a new trigger that inserts a Task when a new Lead is created. After deploying to production, an outside integration is periodically reporting errors.
Which change should the developer make to ensure the integration is not affected with minimal impact to business logic?