Final answer:
The primary force responsible for tides is the gravitational pull of the Moon, which causes differential forces on Earth and results in oceanic tidal bulges.
Step-by-step explanation:
The primary force responsible for the tides is the gravitational pull of the moon (B). This gravitational force is due to the differential impact of the Moon's gravity across various parts of the Earth, which gives rise to tidal bulges in the oceans. While the Sun also has a gravitational influence on the tides, it is the Moon's gravitational pull that is primarily responsible for the characteristic rising and falling of sea levels observed on Earth.
During each lunar day, Earth experiences two high tides and two low tides. This pattern occurs because the Earth rotates through the two tidal bulges caused by the Moon's gravitational force. Literature on the subject credits Sir Isaac Newton with the explanation of tides through his theory of gravity.