Which component is responsible for rendering high-resolution images and video in a computer?

The component responsible for rendering high-resolution images and video in a computer is the Graphics Processing Unit (GPU). The GPU is specifically designed to handle complex graphics calculations and can process multiple operations simultaneously, making it highly efficient for rendering images, animations, and video.

Unlike the Central Processing Unit (CPU), which is a general-purpose processor responsible for executing instructions for various applications and performing general calculations, the GPU excels in parallel processing tasks. This specialization in graphic rendering allows the GPU to deliver smoother graphics performance, important in applications such as gaming, video editing, and graphic design.

The motherboard is the main circuit board that connects all components of the system, but it does not directly render images or video. Similarly, the Network Interface Card (NIC) is responsible for network communication and does not play a role in video or graphical rendering. Thus, the GPU is the critical element in ensuring high-quality visual output on a computer, making it the correct answer.