It began when Galileo tried to use his tidal theory to prove the movement of the Earth around the Sun. Galileo theorized that because of the Earth's motion, borders of the oceans like the Atlantic and Pacific would show one high tide and one low tide per day.
At the lowest angle. Closest to the horizon
Endemic diseases result in a decreasing population, so with that said you can rule out choices B and D.
Among the two left, letter A is the most appropriate answer. Not all endemic diseases have an effect on the number of children a population will have. So if we are speaking about endemic diseases in general, the answer is:
A. Endemic diseases can result in decreasing population numbers: many people die form diseases, and others move away from or avoid moving to places where diseases are rampant.
Why do tides impact ocean? its because the moon and sun's pull cause two bulges or high tides in the ocean on opposite sides of the earth. However, when the sun and the moon reinforce each others gravitational pulls, they create larger than normal tides called spring tides. Hope it helps