Final answer:
The main cause of Earth's tidal bulges is the Moon's gravitational pull, which exerts a differential force on Earth, stretching it slightly and causing water to form bulges on the sides closest to and farthest from the Moon.
Step-by-step explanation:
The primary cause of the tidal bulges on Earth as a result of the moon's gravitational pull is c) Moon's gravitational pull. The Moon's gravity acts differently on various parts of the Earth due to the distance between them, with the near side experiencing a stronger pull than the far side. This differential gravitational force causes the Earth to stretch slightly, resulting in a bulge on the side closest to the Moon and another on the opposite side because Earth itself is pulled toward the Moon more than the water on this far side.
As Earth rotates, it moves through these bulges, leading to the twice-daily tides experienced on most coastlines. This process is explained by both the flow of water over Earth's surface toward the regions beneath and opposite the Moon and the elongation of the Earth into a bulge, largely evident within the oceans. The phenomenon is complex and is further influenced by the Sun's gravitational pull and Earth's geographical features.