Which of the Following Experiments CANNOT Be Modelled by a Poisson

Multiple Choice

Which of the following experiments CANNOT be modelled by a Poisson distribution?

A) the number of calls received by a switchboard during a given period of time
B) the number of bacteria per small volume of fluid
C) the gender of individuals going through a security check at an airport in a given hour
D) the number of customer arrivals at a checkout counter during a given minute