Concept:The spherical shape of the Earth is supported by observations such as the curved horizon, moving ships, and circular shadows; coastal submergence is related to changes in sea level or land level, not the shape of the Earth.
Explanation:The spherical shape of the Earth is confirmed by several natural observations.
A ship moving away from an observer appears to sink hull-first below the horizon because the Earth's surface curves away.
From a high altitude, the horizon appears circular, which is expected when viewing a sphere.
During a lunar eclipse, the shadow cast by the Earth on the Moon is curved and circular, proving that the Earth is round.
Coastal submergence, however, happens when sea levels rise or coastal land sinks.
This indicates a change in the relative level of land and sea, but it does not provide evidence about the Earth's overall shape.
Therefore, coastal submergence is not a proof of the spherical shape of the Earth.
Answer:D. Coastal submergence