passage:
If experiments and observations show that high and low tides in the Pacific Ocean are caused by the moon’s location in its orbit, and the same tides in the Indian and Atlantic Oceans are also caused by the moon’s location in its orbit, we must conclude that the moon is responsible for high and low tides in all oceans.

Which key detail is most important for supporting the central idea of the passage?

The moon orbits the Earth.
The Pacific Ocean has high and low tides.
The moon’s location in its orbit affects all of the oceans.
The moon’s location in its orbit can be easily observed from the Earth.