What can be said about a completely submerged object resting at the bottom of the ocean?

it's B because the density of water is 1, anything greater than that will sink and anything lesser that 1 like 0.99 and down will float. the buoyant force is equal and opposite ( it's like action-reaction forces ) so if you threw the object with a density of 50 N the buoyant force is 50 N so all that it depends on is the density of that object.