The quantity of dissolved oxygen in water is influenced by which of the following factors?

The quantity of dissolved oxygen in water is significantly influenced by temperature, pressure, and salinity.

Temperature plays a fundamental role; as water temperature increases, the solubility of oxygen decreases, meaning warmer water can hold less dissolved oxygen compared to cooler water. This is crucial in aquatic environments, as temperature variations can directly impact the oxygen levels available for organisms living there.

Pressure also affects dissolved oxygen levels. At higher pressures, such as those found at greater depths in the ocean, gas solubility—including oxygen—increases because the gas molecules are compressed into the liquid. Conversely, at lower pressures, gas solubility tends to decrease.

Salinity, while it might seem less intuitive, also affects the solubility of oxygen in water. As salinity increases, the amount of dissolved oxygen that water can hold decreases; this is because the presence of salt ions in the water interferes with the solvation of oxygen molecules.

Considering these factors, the selected answer is comprehensive as it accurately represents critical variables that influence dissolved oxygen levels in aquatic systems.