If you were performing research within a police department and you wanted to ensure that an equal number of officers from each rank and division were included, but you want to use a method of selecting them based on probability, what would you choose as your method?

Systematic sampling, the population size is divided by your sample size to provide you with a number, k, for example; then, from a random starting point, you select every kth individual. For example, if your population size was 2,000 and you wanted a sample of 100, you would select every 20th individual.

Ithink it's a, but i might be wrong