Legionella Pneumophila Is a Gram-Negative Bacterium That Can Cause Legionnaires

Legionella pneumophila is a Gram-negative bacterium that can cause Legionnaires' disease in immunocompromised individuals.Much of its success is attributed to its ability to form a biofilm in the lungs of its host.In this instance, what is the best explanation for the advantage conferred by biofilm formation?

A) The formation of a biofilm prevents individual bacterial cells from drying out.
B) Biofilm formation prevents host immune cells from attacking the bacteria present.
C) The biofilm matrix hampers penetration of antibiotics used to kill L. pneumophila.
D) L. pneumophila recruits other bacterial species, thus causing secondary infections that suppress the immune response.
E) The biofilm causes an increase in nutrient exchange between host cells and the pathogen.