A pending Chatter post is a post that has been scheduled to be published at a future date and time. However, if the user who created the pending Chatter post is deactivated before the scheduled date and time, then the pending Chatter post will be canceled and will not be published. This is because deactivated users cannot create or edit posts in Chatter. References:
https://help.salesforce.com/s/articleView?id=sf.collab_scheduled_posts.htm&type=5
https://help.salesforce.com/s/articleView?id=sf.collab_deactivated_users.htm&type=5

To make a tab hidden in the All App Launcher or visible in any app, but still allow a user to view records that would normally be found under this tab, the administrator should use Tab Settings on a profile. Tab Settings control the visibility and default behavior of tabs for each app in an org. The administrator can set a tab to Hidden, which means it will not appear in any app or in the All App Launcher, but users can still access records via other means such as search or reports. Object Permissions, App Permissions, and Org-Wide Defaults are not related to tab visibility. References:
https://help.salesforce.com/s/articleView?id=sf.customize_tabs.htm&type=5

A support process is a feature that allows administrators to define and enforce the stages that a case or work order must go through based on its record type. A support process determines which values are available for the status field for each record type. If a support process omits a certain value for the status field, such as Closed, then users will not be able to see or select that value when working with cases or work orders of that record type. References: https://help.salesforce.com/s/articleView?id=sf.customize_supporthome.htm&type=5

Campaign hierarchy is a feature that allows administrators to organize campaigns into a parent-child relationship, where the parent campaign represents a larger initiative and the child campaigns represent smaller or more specific activities within that initiative. Using campaign hierarchy can help Ursa Major Solar report on campaign ROI by month and series by creating a parent campaign for the series of networking events and creating individual child campaigns for each monthly event. The parent campaign can show the aggregated metrics and ROI for the entire series, while the child campaigns can show the metrics and ROI for each month.
Adding different record types for the monthly event types, creating individual campaigns that all have the same name, or configuring campaign member statuses to record which event members attended are not solutions for reporting on campaign ROI by month and series; they either do not group campaigns into a hierarchy or do not track campaign metrics or ROI. References:
https://help.salesforce.com/s/articleView?id=sf.campaigns_hierarchy.htm&type=5

A list view is a feature that allows users to filter and display records based on certain criteria and fields. A Kanban view is a feature that allows users to view records as cards organized by columns that represent stages in a process such as opportunity stages or case statuses. Users can switch between list view and Kanban view by clicking on a toggle button on any object tab that supports Kanban view such as opportunities or cases.
Users can also edit records by dragging and dropping cards from one column to another or by clicking on an inline edit icon on each card. In this case, the administrator can create a list view on the opportunity object that filters opportunities by expected close date in the next 90 days; and recommend users switch the view to Kanban to edit opportunities by drag and drop. References:
https://help.salesforce.com/s/articleView?id=sf.lex_list_views.htm&type=5
https://help.salesforce.com/s/articleView?id=sf.kanban_view.htm&type=5