Which of the following is a key characteristic of vector graphics?

Vector graphics are defined by their use of mathematical equations to create shapes, which allows them to be infinitely scalable without loss of quality. This means that whether a vector graphic is displayed at a small size on a business card or blown up to a large banner, it will maintain its clarity and sharpness. This is a fundamental characteristic that sets vector graphics apart from raster graphics, which are made up of pixels and can lose clarity when resized.

The other options highlight characteristics that do not apply to vector graphics. For instance, raster graphics are resolution-dependent, meaning that they lose quality when scaled up. Additionally, the pixel-based structure of raster graphics is in stark contrast to the mathematical representation of vector graphics. Lastly, while photographs are typically best represented through raster graphics, vector graphics are more suited for illustrations, logos, and designs that require scalability and clean lines.