Which sequence correctly summarizes the standard broth dilution method for determining MIC?

• A. Mix equal amounts of antibiotic and bacterial suspension on agar, let the mixture dry, then use turbidity measured spectrophotometrically to determine the lowest antibiotic concentration that causes agar clearing.
• B. Prepare serial dilutions of antibiotic in liquid growth medium, inoculate each tube with a standardized bacterial inoculum, incubate, and read MIC as the lowest concentration with no visible turbidity.
• C. Apply antibiotic discs to a liquid broth surface and measure the diameter of broth clearing around each disc to determine MIC, with the largest clearing corresponding to the lowest MIC value.
• D. Use broth with no bacteria, incubate with serially increasing amounts of antibiotic and measure pH changes to infer bacterial susceptibility, with stable pH indicating inhibition and therefore MIC.

Answer: (B)