Final answer:
To display all laptops within a category immediately after a category selection without further user interaction, the 'Auto Update' feature should be used.
Step-by-step explanation:
The requirement described by the student involves automatically updating a list of laptops based on the category selected from a drop-down menu without any further interaction from the user. Among the options provided, the best fit for this need would be Auto Update.
The Auto Update feature typically refers to the capability within a system to refresh data or content without manual input, which in this case would be to show all laptops within the selected category instantaneously after the selection is made.
The option that meets this requirement is Commerce library function. The Commerce library function is a feature provided by e-commerce platforms that allows for advanced customization of product configuration. It includes the ability to create drop-down lists and display specific products based on the user's selection.
Therefore, the correct option is D. Auto Update.