Which of the following image file types is often used for graphics with transparent backgrounds?

The .png (Portable Network Graphics) file format is widely used for graphics that require transparent backgrounds. This is a key feature of the .png format, which supports an alpha channel. The alpha channel allows for varying levels of transparency, enabling graphics to blend seamlessly with different backgrounds. This makes .png ideal for web graphics, icons, and logos, where maintaining a transparent background without losing image quality is crucial.

In contrast, other file formats such as .bmp (Bitmap) and .jpeg (Joint Photographic Experts Group) do not support transparency. .bmp typically has a solid background color and does not handle transparency well, while .jpeg compresses images in a way that discards certain data, including transparency. Although .tiff (Tagged Image File Format) can support transparency, it is generally more commonly used in print and professional photography rather than for web graphics and does not have the same level of widespread browser support as .png. Hence, the .png format is the most suitable choice for this context.