A solar eclipse occurs when the Moon's shadow falls on the Sun.

• A. Moon's shadow falls on the Sun
• B. Sun's shadow falls on the Moon
• C. Earth's shadow falls on the Moon
• D. Moon passes behind Earth

Answer: (A)

Eclipses happen when Sun, Moon, and Earth line up so that one body blocks sunlight for the other. For a solar eclipse, the Moon sits between the Sun and Earth, and the Moon’s shadow falls on Earth, blocking sunlight along a narrow path. Saying the Moon’s shadow hits the Sun would imply the Sun is being blocked at its location, which isn’t how this event works. The other scenarios describe a lunar eclipse, where Earth’s shadow falls on the Moon or the Moon moves behind Earth relative to the Sun. So the correct idea is that the Moon between the Sun and Earth casts its shadow onto Earth during a solar eclipse.