For years, scientists have proposed the idea that Mars was once covered by two huge oceans. However, ridges of rock in the northern hemisphere that seem to resemble a shoreline are too hilly to be the edges of an ocean. If it could be shown that something caused an imbalanced portion of the planet's mass to shift from these ridges of rock toward the equator, where the mass now lies, it is possible that the ridges were once actually smooth.

Which of the following can be inferred from the statements above?

a)If it is determined that the ridges of rock in the northern hemisphere of Mars were never smoother than they now are, oceans did not exist on the planet.
b) The discovery that some of Mars' equatorial mass was once part of northern-hemisphere rock ridges would support the idea that the planet was once covered by oceans.
c) If the rock ridges in the northern hemisphere of Mars were smooth at one time, some the planet's mass was once closer to the equator
d) In order for a planet to have oceans, a portion of the planet's mass must have been shifted towards the equator.
e) There is general agreement in the scientific community that Mars does not have the right atmospheric conditions to support an ocean.

My answer a as it talks about ridges being smoother or not as that is the measure of presence of ocean..