Which type of contamination can affect both taste and smell in water?

The correct choice indicates that secondary contaminants can significantly impact both the taste and smell of water. Secondary contaminants typically encompass taste- and odor-affecting substances that may not pose a direct health risk but can influence the overall sensory characteristics of drinking water. These can include compounds like iron, manganese, and certain organic materials that are present in lower concentrations but can still result in noticeable changes to the water's sensory profile.

It's important to note that while microbial contamination may lead to unpleasant odors or tastes, it is primarily a health concern rather than a direct indicator of non-toxic sensory issues. Organic contaminants typically include substances like pesticides and solvents, which can also affect taste and smell, but they are often monitored for health impacts rather than sensory effects. Inorganic contaminants are usually defined by their chemical properties and health implications, rather than their influence on the sensory attributes of water.

This distinction helps clarify why secondary contaminants are most aligned with changes in taste and smell, emphasizing the importance of monitoring and addressing these aspects in water quality management.