Concept:A lunar eclipse happens when the Earth blocks sunlight from reaching the Moon.Explanation:The Moon has no light of its own, so it reflects light from the Sun.When the Earth comes directly between the Sun and the Moon, the Earth’s shadow falls on the Moon.This causes the Moon to darken, producing a lunar eclipse.The Moon coming between the Sun and the Earth would cause a solar eclipse, not a lunar eclipse.Answer:The correct option is D — Earth casts its shadow on the Moon.