Neither
I only
II only
I and II
Explanation
Correct answer: A.
Choice A is correct. The purpose of surveying a random sample of residents is to approximate the percent of the town residents that are satisfied with the concession stand. The sample doesn't necessarily get the same result as surveying every resident of the town, nor would another sample necessarily have identical results. Therefore, although it's possible that either statement I or statement II could prove true by surveying every resident of the town, these statements cannot be proven true solely based on the results of the sample.
Why the other choices are wrong
Choice B
Choice B is incorrect because surveying a sample of the town residents may not have the same result as surveying all the town residents.
Choice C
Choice C is incorrect because surveying a different sample of residents could yield different results.
Choice D
Choice D is incorrect because surveying a different sample of residents could yield different results.