The moon's observed motion across the sky is PRIMARILY due to the A)
rotation of the moon.
B)
rotation of the earth.
C)
orbit of the moon around the earth.
D)
orbit of the earth around the moon.

I think that rotation of the moon is the correct one

Explanation:

C) orbit of the moon around the Earth

answers: to make sure that all of the broken pieces of tablet were added to the water, to allow for fair comparison of all three trials, with different particle sizes to avoid experimental error

that tool would be a compass