Step 1 :The binomial distribution has two outcomes: success or failure.
Step 2 :In this case, the nationality of a citizen can be more than two, so it does not satisfy the requirement of a binomial distribution.
Step 3 :Also, the probability of each nationality may not be the same, so the probability of success does not remain the same in all trials.
Step 4 :Therefore, this is not a binomial distribution.
Step 5 :\(\boxed{\text{(C) It is not binomial because there are more than two possible outcomes.}}\)