What is affected by both the gravitational influence of the Moon and the Sun?

The correct answer is tides because they are the result of the gravitational forces exerted by both the Moon and the Sun on Earth's oceans. The Moon has a more significant effect on tides due to its closer proximity to the Earth, but the Sun's gravity also plays a crucial role in the overall tidal patterns. When the gravitational pull from these celestial bodies aligns, such as during full moons and new moons, it leads to higher high tides and lower low tides, known as spring tides. Conversely, when the Sun and Moon are at right angles to each other, during the first and third quarters of the moon phase, the gravitational pull is weaker, resulting in neap tides with less pronounced differences between high and low tides.

In contrast, the other options listed are influenced by different natural processes. Waves are primarily affected by wind patterns and other kinetic forces rather than gravitational influences. Seasons are determined by Earth's axial tilt and its orbit around the Sun. Weather is influenced by atmospheric conditions such as temperature, pressure, and humidity, rather than directly by the gravitation of the Moon and Sun.