Why are people not able to scuba dive to the deepest parts of the ocean

A as you go deeper into the ocean temperature increases to much for a body to withstand

B as you go deeper into the ocean temperature decreases and pressure increases to much for a body to withstand

C as you go deeper into the ocean temperature and pressure increases too much for the body to withstand

D as you go deeper into the ocean temperature and pressure decreases too much for the body to withstand

Plz help