What factors influence the density of seawater?

The correct choice highlights the key factors that influence the density of seawater, which are temperature, salinity, and pressure.

Temperature plays a significant role in density; as water warms, it becomes less dense. Conversely, as temperature decreases, seawater becomes denser. Salinity also affects density: higher salinity means more dissolved salts, which increases the water's density. Lastly, pressure influences density as well, particularly in deeper waters. As depth increases, pressure rises which compresses water molecules together, also contributing to increased density.

This multifaceted relationship is essential when studying oceanography and underwater physics, as variations in these factors can significantly impact buoyancy, the behavior of marine life, and the distribution of ocean currents. By understanding these influences, divers and marine scientists can better predict environmental conditions and safety measures while underwater. Other options do not adequately consider the combined effects of these three interconnected factors on seawater density.