Which object has the greatest inertia?
Inertia is affected by the mass of the object and the velocity of the object. The greater the mass/velocity, the more inertia the object has. Objects with high inertia are more difficult to stop and start moving, objects with low inertia are easier to stop and start moving. So you have to imagine which of those four would be the hardest to start/stop moving. Since ocean liners are obviously much much heavier than options 1, 2 or 3, an ocean liner would have the greatest inertia.
