Explanation:

- Challenger Deep: This is the correct answer. It is the lowest known point on Earth's seabed, located in the Mariana Trench in the Pacific Ocean. It reaches depths of around 36,000 feet or 10,994 meters.

- Factorial Deep: This is not a recognized geographical location. It may be a confused term or fictional.

- Great Blue Hole: Located in the Caribbean Sea off the coast of Belize, this is a large marine sinkhole and part of the Great Barrier Reef Reserve System. It is not the Earth's lowest point.

- Great Barrier Reef: This is the world's largest coral reef system, located in the Coral Sea off the coast of Queensland, Australia. It is famous for its biodiversity, not depth.