Mount Everest is the highest mountain in the world, located in the Himalayas on the border between Nepal and Tibet.
Chomolungma is the Tibetan name for Mount Everest. The name means "Goddess Mother of the World" in Tibetan.
Sagarmatha is the Nepali name for Mount Everest. The name means "Forehead of the Sky" in Nepali.
Kamet is a different mountain located in the Garhwal Himalayas in Uttarakhand, India. It stands at 7,756 meters (25,446 feet) and is the second-highest mountain in the Garhwal region.
Mount Everest, Chomolungma, and Sagarmatha are three different names referring to the same mountain.
Kamet is an entirely separate mountain.
Therefore, Kamet (Option 3) is the odd one out.