What action is required to visualize and change relationships using Schema Builder?

Using the Schema Builder tool to drag and drop is the appropriate action to visualize and modify relationships between objects within Salesforce. Schema Builder is specifically designed for this purpose, providing a user-friendly graphical interface that allows users to see and interact with the data model. This means you can easily visualize how different objects are related and make changes to their relationships by dragging lines between objects or creating new fields.

This tool eliminates the complexity often associated with coding or manipulating relationships programmatically, which can involve more technical knowledge and understanding of the underlying code. Instead, Schema Builder allows users at various skill levels to intuitively manage their data model visually.

Other methods, such as adjusting settings in the Object Manager, primarily focus on configurations and do not provide the same interactive visualization and relationship manipulation capabilities. Accessing the Developer Console or using Apex to manipulate relationships would require coding knowledge and is not as straightforward as using the drag-and-drop functionality within Schema Builder.