What is the standard for broadcast distribution in the United States?

The correct choice is NTSC, which stands for National Television System Committee. This television broadcasting standard was established in the United States and has been predominantly used for analog television broadcasts. NTSC specifies the resolution and frame rate, which is 480i (interlaced) at 29.97 frames per second.

While other standards such as PAL (Phase Alternating Line) and SECAM (Séquentiel Couleur à Mémoire) are employed in different regions of the world—primarily Europe and parts of Africa—the NTSC standard has historically been the primary system for television broadcasts in the U.S.

ATSC (Advanced Television Systems Committee) is another important standard, but it pertains to digital television rather than the traditional analog format established by NTSC. Although ATSC has replaced NTSC for digital broadcasts in the U.S., the framing of the question seems to focus on the older analog standard, which is why NTSC is the correct answer.