Answer:
A. Probability sample
Step-by-step explanation:
A Probability Sampling may be defined as the sampling technique where a sample from the larger population are taken or selected using the method which is based on the theory of probability.
In a probability sample, the probability or the chance of each of the element to be included in the sample is non zero and known. A cluster sample is an example of a probability sample.
Hence the correct option is (A).