A $0.5 \mathrm{McF}$ Arland Standard Is Used in All Microbiology Labs When Performing

A $0.5 \mathrm{McF}$ arland standard is used in all microbiology labs when performing a Kirby-Bauer assay. This standard allows for a visual turbidity reading to achieve reproducibility in the number of bacteria inoculated on a plate. This is most important because:

A) multiple antibiotics testing requires that bacteria be spread evenly around the plate
B) the MIC value can only be achieved by serial dilutions
C) number of organisms placed on an agar surface is inversely proportional to the size of the zone of inhibition
D) bacterial counts need to be the same across all labs since incubation times can differ
E) bacterial counts need to be the same across all labs since plate sizes in this assay can differ