The correct answer is C. Systematic sampling technique.
Systematic sampling is a probability sampling technique where every kth element in the population is selected for inclusion in the sample, where k is a constant known as the sampling interval. This technique is easy to implement and can be used with both finite and infinite populations.
Area sampling is a probability sampling technique where the population is divided into geographical areas and a sample of these areas is selected. The elements within each selected area are then included in the sample. This technique is often used when the population is spread out over a large geographic area.
Purposive sampling is a non-probability sampling technique where the researcher selects the elements for the sample based on their judgment about which elements will be most informative. This technique is often used when the population is difficult to reach or when the researcher is interested in a specific group of people.
None of the above is not a correct answer.