Answer:
Osa
Explanation:
Relative distances
Osa is in a submarine 200 feet under sea level. We can say its distance to sea level is 200 feet
Jill is 311 feet above sea level, her distance to sea level is 311 feet
We can say Osa is closest to sea level
If we consider ground level to the reference where distances are measured from above, then we must say Osa is closest to it because she is below sea level and naturally, closer to the ground below it