Final answer:
To measure bacterial contamination in processed peanut butter, the total plate count method is used, as it provides an accurate estimation of viable bacteria present in the sample.
Step-by-step explanation:
To measure the concentration of bacterial contamination in processed peanut butter, the most appropriate method would be B. total plate count. This technique involves spreading a diluted sample of the peanut butter on an agar plate and incubating it for a period of time to allow bacteria to grow. After incubation, visible colonies are counted, and the number of colonies is used to estimate the concentration of bacteria in the original sample. Methods like turbidity measurement, dry weight measurement, and direct counting of bacteria under a microscope can also be used in different contexts, but for processed food like peanut butter, total plate count is typically considered the standard method due to its accuracy in quantifying viable bacteria.