I do not see the four choices, but here are the likelihoods; biology, chemistry, geology, and physics.
This is because there are four main components of study when it comes to becoming an oceanographer:
biological – studying marine plants and animals
physical – exploring water temperature, density, wave motion, tides and currents
geological – examining the structure and make-up of the ocean floor
chemical – analysing the chemicals in sea water and the impact of pollutants
