Answer:
The correct answer is option A, Moon phases
Step-by-step explanation:
The moon phases are primarily caused due to the different angle of orientation when visualized from the planet earth. The prime reason for changing faces of the moon is its position relative to the position of sun and earth. When the moon is passing in front of the earth, all its bright phases occur in that phase of the lunar cycle as moon gets light from sun which makes it visible on earth. While when moon is in a position where earth lies in between the moon and sun, the moon goes through its dark phases as the light of sun is restricted by the planet earth.