Identify the valid Import sections and the required columns for each section.

1. Version, Required column: version name

2. Hierarchy, Required columns: hierarchy name, top node

3. Hierarchy, Required columns: hierarchy name

4. Node, Required column: node name

5. Relationship, Required columns: parent node name, child node name

6. Hierarchy Node, Required columns: hierarchy name, node name

7. Hierarchy Node, Required columns: hierarchy name