Explanation
If you have entity information in your default view for your planning application, but you also want that entity information to be accessible in another view, you can use the following method to accomplish this: identify the node set used by the entity dimension, create a viewpoint in a different view, and then point to that same node set. This way, you can reuse the same node set for different viewpoints in different views. You cannot use the other methods, because they are not supported by Oracle Enterprise Data Management Cloud. You cannot point to a view from another view, because views are collections of viewpoints and do not have a direct relationship with each other. You cannot copy a view and create a request or run a validation, because these actions are not related to creating views. You cannot point to a viewpoint from another viewpoint, because viewpoints are related to node sets and hierarchy sets rather than other viewpoints. References: Working with Views - Oracle Help Center1; Working with Viewpoints - Oracle Help Center

Explanation
All items in the request are validated using your data access except the enriched item, which is validated during the approval phase using the enricher's data access: This option is correct because when a request is pushed back to the submitter, the enriched item is preserved and validated using the enricher's data access during the approval phase. The rest of the items are validated using the submitter's data access when the request is submitted again.
References:
* https://docs.oracle.com/en/cloud/saas/enterprise-data-management-cloud/edmra/approving-and-enriching-r

* You need to create a validation view with multiple viewpoints from different dimensions so you can maintain all your application information in one place: This option is correct because a validation view is a type of view that allows you to create multiple viewpoints from different dimensions and validate them against each other. You can use a validation view to maintain all your application information in one place and check for any errors or inconsistencies.
* You need to create a view to give users access to a limited set of data: This option is correct because a view is a type of data chain object that defines the scope of data that users can access and work with.
You can create a view to give users access to a limited set of data by specifying the node sets and hierarchy sets that are included in the view.
* You need an alternate view to share, compare, and map information across multiple applications:
This option is correct because an alternate view is a typeof view that allows you to create multiple viewpoints from different applications and share, compare, and map information across them. You can use an alternate view to synchronize and govern data across registered applications.

Explanation
When a data manager submits a request in a view that has subscriptions defined, the system generates subscription requests based on the subscriptions and assignees for each viewpoint. If multiple viewpoints have the same assignee, the system bundles the request items into a single subscription request for that assignee.
References: Creating, Editing, and Validating Subscriptions - Oracle Help Center1

Explanation
Mapping keys are used to specify the source node types mapped to target node types and to define a location name to export the mapping data. The following statements are true about mapping keys: mapping keys consist of a location, source node type, and target node type; mapping keys control which dimensions are output in the source and target columns of the mapping export. The following statements are false about mapping keys: the system automatically generates mapping keys for each unique location; one mapping key is required per location. You need to manually define mapping keys for each source-to-target relationship using a unique location name. You can have multiple mapping keys for the same location if you have different source node types mapped to the same target node type. References: Defining Mapping Keys - Oracle Help Center1; Exporting Mapping Data - Oracle Help Center