Which code segments should you include in Target 1, Target 2 and Target 3 to complete the code?

Explanation/Reference:
* SPRoleDefinition
The role definition, or permission level, is the list of rights associated with the role. For example, a user with the Read role can browse pages in the Web site and view items in lists. A role definition is a collection of rights bound to a specific object. Role definitions (for example, Full Control, Read, Contribute, Design, or Limited Access) are scoped to the Web site.
* SPWeb.Update
Scenario: User Authorization
A custom role named Wholesale must be created. Wholesale customers must be assigned to this role in order to view the promotions page.
Incorrect:
Not RoleDefinitionCollection: SPWeb does not have a member RoleDefinitionCollection. Not web.Commit(): SPWeb does not have a method Commit().
Not web.AddProperty(CustomRole,_permissions) Just need to create the role, not add permissions.
Reference: SPWeb members; SPWeb methods