Regarding Calculating the Probability of Including a Sample Unit in a Probability

Multiple Choice

Regarding calculating the probability of including a sample unit in a probability sample,which of the following is most accurate?

A) It can be determined with a high level of accuracy.
B) Practically speaking,it may be impossible to calculate the probability precisely.
C) If it cannot be calculated precisely,then the sample is not to be considered a probability sample.
D) Precise estimates are known and may be found in statistical tables.
E) Only professional statisticians can determine the accuracy.