What might be a sign of water contamination from heavy metals?

The correct choice indicates that all the listed signs—cloudiness, unusual colors, and a metallic taste—can be indicators of water contamination from heavy metals.

Cloudiness in water can result from various contaminants, including heavy metals, which may affect the physical properties of the water. The presence of solid particles or the reaction of heavy metals with other substances could contribute to this cloudiness.

Unusual colors, such as a reddish or brown tint, can signal the presence of metals like iron or copper, which can leach into water supplies from corroded pipes or contaminated sources. The color change can be especially pronounced with certain heavy metals that naturally appear in the environment.

A metallic taste is often a direct sensory indication of the presence of heavy metals. When heavy metals dissolve in water, they can impart a distinct metallic flavor, signaling to consumers that the water may not be safe for drinking.

Considering these factors, the conclusion is that all of these signs—cloudiness, unusual colors, and metallic taste—are indeed potential indicators of heavy metal contamination in water, making the option encompassing all of them the most comprehensive and accurate choice.