Concept:The spherical shape of the Earth is confirmed by natural phenomena that show the Earth's curved shadow.Explanation:A lunar eclipse occurs when the Earth comes between the Sun and the Moon.The Earth casts a shadow on the Moon.The edge of this shadow is always curved, not straight.Only a spherical object can cast a curved shadow in all directions.Other evidence includes ship visibility and circumnavigation.The Moon's eclipse therefore directly proves the Earth is spherical.Answer:C. moon's eclipse