Final answer:
The commercial modification of the disk diffusion test for determining antimicrobial susceptibility is called the Kirby-Bauer test.
Step-by-step explanation:
The Commercial Modification of the Disk Diffusion Test
The commercial modification of the disk diffusion test used for antimicrobial susceptibility testing is commonly known as the Kirby-Bauer test. This standardized procedure involves inoculating a Mueller-Hinton agar plate with a bacterial lawn, then placing filter paper disks, which are impregnated with antibacterial drugs, onto the plate. As the antibiotic diffuses from the disk into the agar, zones of inhibition appear around the disks if the bacteria are susceptible to the antibiotics. The size of these zones is measured to determine the susceptibility or resistance of the bacteria to the antimicrobial agents.
The correct answer to the student's question is c) Kirby-Bauer test.