Final answer:
A client-server application that needs only a browser is called a thin-client application, as the server handles most processing work, e.g. web-based email services.
Step-by-step explanation:
A client-server application that requires nothing more than a browser is called a thin-client application. This term is used to describe applications where the server performs most of the processing work, and the client, typically a web browser, requires minimal resources and processing power.
The alternative, a thick-client application, refers to applications where the client does significant processing and may require installation of additional software or resources on the client side.
A client-server application that requires nothing more than a browser is called a thin-client application. In a thin-client application, most of the processing and data management occurs on the server side, and the client (browser) is responsible for displaying the user interface and handling user inputs.
Therefore the correct anser is D) thin-client application.