Final answer:
Opportunistic pathogens such as Legionella, Pseudomonas, and Mycobacterium species have the ability to grow within c) protists, which may enhance their ability to survive in water distribution systems.
Step-by-step explanation:
The answer to the question is C) protists. Opportunistic pathogens such as Legionella, Pseudomonas, and Mycobacterium species have the ability to grow within protists, which may enhance their ability to survive in water distribution systems.
Protists are a diverse group of microorganisms that include amoebae, ciliates, and flagellates. These protists can serve as hosts for the pathogens, providing them with protection and allowing them to multiply within their cells.
For example, Legionella pneumophila, the causative agent of Legionnaires disease, can grow and survive inside amoebae. This enhances its ability to persist and spread in water systems, increasing the risk of infection.