Explanation

MPEG (Moving Picture Experts Group) is a family of standards — MPEG-1, MPEG-2, MPEG-4 — specifically designed for compressing video (e.g., VCD, DVD and digital video). P*64 (Px64), standardised as ITU-T H.261, is a video coding standard developed for videoconferencing that compresses moving pictures at multiples of 64 kbps. Indeo, developed by Intel, is a video codec used for compressing digital video on PCs in the 1990s. Since all three are video-compression formats, the correct answer is 1, 2 and 3.