Which factors can affect visibility underwater?

The correct answer highlights several key environmental factors that affect underwater visibility. Sediment refers to small particles like sand or silt that can be disturbed and suspended in the water, creating murky conditions. Algae can proliferate in response to nutrient levels, leading to green or murky water, which significantly reduces visibility. Weather conditions, such as rain or wind, can also influence visibility by introducing runoff that may carry more sediment or pollutants into the water, further obscuring visibility.

Understanding these factors is crucial for divers, as they can lead to varying conditions that impact safety and the overall diving experience. While other options may contain elements that influence diving in different ways, they do not directly address the primary contributors to underwater visibility as comprehensively as this correct option does.