According to the Oracle Help Center1, shared nodes are nodes that exist under different parents within a hierarchy set or viewpoint. When you insert a node that has children under another parent in the same hierarchy, the node and its children are inserted as shared nodes.

When you want to map two general ledger systems, GL1 and GL2, to a single EPM Planning application, and it is time to synchronize changes by exporting the plan account mappings, the following statement about mapping keys is true: you need two mapping keys, one for GL1-to-Planning and one for GL2-to-Planning. When you export a mapping, you select the location with its associated mapping key. 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. You need to define one mapping key for each source node type mapped to a target node type. For example, if you map two source applications to one target application, you need to define two mapping keys defining the mapping relationship from each source node type to the target node type. Each mapping key is identified by a unique location name that you enter. The location name is used to export the mapping data and by the consuming or external application to import the mapping data. You do not need only one mapping key and location to export the plan account mappings, because this would not specify the correct source-to-target relationships. You do not need to create shadow mapping keys in the target application or one location per mapping key, because these are not supported by Oracle Enterprise Data Management Cloud. Reference: Defining Mapping Keys - Oracle Help Center1; Exporting Mapping Data - Oracle Help Center2

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. Reference: Defining Mapping Keys - Oracle Help Center1; Exporting Mapping Data - Oracle Help Center2

This option is correct because when the approval method is parallel and one approval per group is not selected, the approvers from different groups can approve in any order and the request is approved when the total required number of approvals is met, regardless of which groups they belong to.
Reference:
https://docs.oracle.com/en/cloud/saas/enterprise-data-management-cloud/edmra/creating-approval-policies.html

1. You need the Data Manager or Owner permission to the application to export its dimensions and mappings: This option is correct because the Data Manager or Owner permission is required to export enterprise data from an application to an external application or a file.
2. For Planning and Universal applications, you can export enterprise data using either a connection or a comma-delimited file: This option is correct because Planning and Universal applications support both methods of exporting enterprise data.
Reference:
https://docs.oracle.com/en/cloud/saas/enterprise-data-management-cloud/edmra/exporting-enterprise-data.html