Nanga Parbat (8,126m) is the highest among the options listed. It is the ninth highest mountain in the world and second highest in Pakistan after K2. Nanda Devi (8,163m) is actually higher than Nanga Parbat but is listed as option D, not C. Kamet (7,756m) and Kun Lun (various peaks, none exceeding 7,500m) are lower.