Final answer:
The death rate of bacteria in a given community overtime is a measure that can be used to measure the variability in individuals' susceptibility to being killed by antibiotics.
Step-by-step explanation:
The most appropriate measure to determine the variability in individuals' susceptibility to being killed by antibiotics in bacterial populations is the death rate of bacteria in a given community overtime (option B). By monitoring the death rate, we can observe how effective antibiotics are at killing bacteria and identify the variations in susceptibility among individuals. This measure takes into account the relative vulnerability of different bacteria to antibiotics and provides valuable information for understanding antibiotic resistance and developing effective treatments.