Explanation/Reference: https://docs.servicenow.com/bundle/orlando-application-development/page/script/useful-scripts/ concept/c_UsefulSchedulingScripts.html

Comprehensive and Detailed Step-by-Step Explanation:
* Definition of a Spoke:A "spoke" is a scoped application or component of an application that contains Flow Designer actions and integrations. Spokes provide reusable functionality and are typically used to extend the capabilities of Flow Designer.
* Why It's Called a Spoke:
* Spokes are part of the ServiceNow Flow Designer framework.
* They contain predefined actions that are reusable across multiple flows. For example, an "Email Spoke" might include actions for sending emails or managing email configurations.
* Why Other Options Are Incorrect:
* Option B (Flow): This refers to an individual flow, not the application containing reusable actions.
* Option C (Bundle): There is no such term as "Bundle" specific to Flow Designer in ServiceNow.
* Option D (Action): While flows contain actions, the scoped application that houses these actions is referred to as a spoke.
References:
* ServiceNow Developer Documentation on Flow Designer Spokes.

A possible reason to build a custom app is to fulfill a specific use case on internal processes. For example, you may want to digitize a manual process that is not covered by an existing ServiceNow solution, such as managing inventory, tracking expenses, or scheduling events. Building a custom app on the Now Platform can help you automate workflows, improve data quality, and provide better user experiences. The other options are not valid reasons to build a custom app. To avoid using a code repository like GitHub or GitLab is not a reason to build a custom app, as you can still use source control integration with your custom app development. To create a custom integration for a 3rd party system is not a reason to build a custom app, as you can use integration tools such as IntegrationHub or REST APIs to connect with external systems without creating an app. To replace ServiceNow base tables is not a reason to build a custom app, as it is not recommended to modify or delete base tables that are essential for ServiceNow functionality. Reference: Build Custom Apps in ServiceNow - eBook

Explanation/Reference:
Reference https://docs.servicenow.com/bundle/orlando-application-development/page/build/applications/ concept/c_ApplicationScope.html#r_ExampleNamespaceIdentifiers