What is a table within the application database that stores sendable subscriber data as well as relational data?

The correct answer is a Data Extension because it serves as a flexible database table specifically used in Salesforce Marketing Cloud to store subscriber information and other related data. Data Extensions allow marketers to maintain complex datasets and can contain various fields to accommodate different types of information.

They can support both sendable subscriber data, which means they can be used in email communications for sending marketing messages, as well as relational data that connects with other data sources to provide a comprehensive view of customer interactions. This versatility makes Data Extensions a crucial feature for managing and segmenting audiences in marketing campaigns effectively.

In contrast, other options such as Data Table, Data List, and List do not have the same functionality. For example, Data Table is often used to refer broadly to any set of data arranged in a table format but does not specify the capabilities relevant to subscriber management in Marketing Cloud. Similarly, Data List and List typically refer to older or less functional frameworks for compiling subscriber data that do not offer the relational capabilities and flexibility that Data Extensions do.