The general rule in statistics is that the sample size can never exceed the size of the whole population. This means that any number larger than 32,000 cannot be a possible sample size.
Looking at the options given:
Option A: 3,200,000 - This number is significantly larger than the total population size of 32,000, so this cannot be a possible sample size.
Option B: 32,000,000 - This number is also much larger than our total population size of 32,000, so this cannot be a possible sample size either.
Option C: 3,200 - This number fits within the total population size of 32,000, making it a possible sample size.
Option D: 320,000 - This number is larger than the total population size of 32,000, meaning this cannot be a possible sample size.
So, the only possible sample size for a population of 32,000 is option C: 3,200.