Final answer:
During a total solar eclipse, an observer on the side of the Moon facing Earth would see a dark area moving across the face of Earth. This is known as a solar eclipse and occurs when the Moon's shadow partially or completely blocks the Sun's light.
Step-by-step explanation:
During a total solar eclipse, an observer on the side of the Moon facing Earth would see a dark area moving across the face of Earth (option D). During a total solar eclipse, an observer on the side of the Moon facing Earth would see a dark area moving across the face of Earth. This is known as a solar eclipse and occurs when the Moon's shadow partially or completely blocks the Sun's light.
The Moon's shadow would be casting a shadow on Earth, partially or completely blocking the Sun's light depending on the observer's location. This phenomenon is known as a solar eclipse and can only be observed when the Sun, Moon, and Earth are properly aligned.