The correct answer to this open question is the following.
Although you forgot to attach the options for this question we can say the following.
A cruise ship makes its way from one island to another. the ship is in motion compared with which reference point?
The correct answer is "a lighthouse on a nearby island."
In this case, that is the function of the lighthouse. To be the point of reference or the guiding element that the captain of the ship is going to use to keep the ship's trajectory correct.
Although there are uncontrollable external elements such as heavy storms, fog, or bad weather, the captain of the ship is going to be guided by the lighthouse.
