To help your investigation, here is some more data about the farm. The chicken population was started with chicks from a different farm.
Chickens are raised in barns where bacteria can spread easily between chickens.
CJ, E. Coli, and Salmonella bacteria are all present in the barns.
Some of the E. Coli and Salmonella bacteria have alleles that make them resistant to the FQ antibiotic.
To stop disease from growing in the barn, the FQ antibiotic is fed to the chickens a lot.

Choose which way of evolution caused the FQ antibiotic resistance.
Form a hypothesis that explains your choice. You will be able to revise your hypothesis after performing experiments.