What characteristic defines a responsive design?

A responsive design is defined by its ability to adapt to various screen sizes and orientations. This characteristic is essential in today's digital landscape, where users access content from a multitude of devices, including smartphones, tablets, laptops, and desktops.

Responsive design ensures that a website or application provides an optimal viewing experience by adjusting its layout, images, and elements according to the device being used. This adaptability improves usability and accessibility, allowing users to navigate and interact with the content seamlessly, regardless of their device type.

The other options highlight misconceptions about responsive design. For instance, a design that is only compatible with desktops does not account for the diverse range of devices in use today and fails to deliver a user-friendly experience across different platforms. Similarly, a design that does not adapt to different screen sizes or has a fixed layout negates the very principle of responsiveness, as it would lead to poor usability on devices with varying dimensions, ultimately driving users away.