The scientist hypothesizes that phenazines serve as molecular pipelines that give interior bacteria access to essential nutrients in the surrounding environment of the colony.
Why? Well, we actually have no direct evidence for this hypothesis. We merely know that some colonies of bacteria produce antibiotic molecules called phenazines, which they use to fight against other bacteria.
Answer choice (A) states: "Bacteria colonies that do not produce phenazines form wrinkled surfaces, thus increasing the number of bacteria that are in direct contact with the surrounding environment."
So if those bacteria colonies that do not produce phenazines end up forming wrinkled surfaces, which increase the number of bacteria that have direct contact with the surrounding environment, this wrinkled surface is a reaction to not having phenazines, i.e. it is a reaction in order to make up for the lack of phenazines.
We know it's important for the bacteria to have access to nutrients in the environment surrounding the colony, since the argument tells us that these nutrients are essential to the bacteria. Thus, if the lack of phenazines causes the bacteria colonies to form wrinkled surfaces in order for them to better access the surrounding environment, the presence of phenazines must in some way allow the interior bacteria to have access to the essential nutrients in the environment surrounding the colony.
Thus, answer choice (A) supports the scientist's hypothesis that phenazines serve as molecular pipelines allowing interior bacteria success to essential nutrients in the surrounding environment.
Hope that clears things up! Please let us know if you have any other questions.
