What is a dataset?

A collection of data from across your HubSpot account that can then be used in custom reports
A distinct organizational entity or segment within a company that operates independently with its own specific goals, workflows, and resources
A report (usually in a table form) you build using your custom data to derive unique insights about your strategies, systems, or customers
A way to visualize the objects, associations, and event data found within your HubSpot account

The correct answer is:

A collection of data from across your HubSpot account that can then be used in custom reports