Question

The main cause of the changing location of the tides on earth is
-rotation of the Earth on its' own axis
- magnetic forces of the Moon
- the revolution of the Moon around the Earth ***
-the position of the Sun

Answer 1

I disagree. The tide is high twice a DAY because the earth spins under the moon putting the moon over Gloucester once a day and exactly opposite Gloucester every day. In both cases the water rises either toward the moon when you are under it or away from the moon when you are opposite the moon, further from the earth moon center of gravity and the water spins away due to centripetal acceleration.
If it were due to the motion of moon around earth you would get 2 tides a MONTH (it does have a smaller effect, leading to increased full and new moon tides called spring tides or the weather folks (landlubbers) call the "astronomical tides")

Answer 2

so then it has to be "a" since the earth revolves in its axis in a 24 hour period of time

Answer 3

Yes

Answer 4

Did no teacher do the ping pong ball, tennis ball and soccer ball thing in your class?

Answer 5

so then it has to be "a" since the earth revolves in its axis in a 24 hour period of time