I think the correct answer would be the last option. The ocean zone which has the lowest water pressure would be the uppermost zone which is the Epipelagic zone. This zone is also called as the euphotic zone or the sunlit zone. It is the region which receives the most sunlight in order to allow photosynthesis.
Answer: Atomic Nucleus!
Explanation: All atoms have a dense central core called the atomic nucleus. Forming the nucleus are two kinds of particles: protons, which have a positive electrical charge, and neutrons, which have no charge.
(Yes, it was from google.)
