Final answer:
Sensitivity testing is used to determine a pathogen's susceptibility to a particular antibiotic, which aids in selecting appropriate treatments for bacterial infections.
Step-by-step explanation:
Sensitivity testing is used primarily to determine the susceptibility of a microorganism to various antimicrobial drugs. One of the common methods for this testing is the Kirby-Bauer disk diffusion test, which involves placing disks impregnated with antimicrobial agents on a bacterial culture to observe zones of inhibition. These zones are measures of how effective the drug is at inhibiting bacterial growth and are compared with standardized charts to determine whether the microorganism is susceptible or resistant to a specific antibiotic. Such testing is critical for guiding the selection of appropriate antibiotic therapy in clinical settings. When considering the given options, the correct answer is c. A pathogen's susceptibility to a particular antibiotic. This process is vital for managing bacterial infections effectively, especially with the rise of antibiotic resistance.