Answer: Simple random
Explanation: In statistics, a simple random sample is a subset of individuals chosen from a larger set. Each individual is chosen randomly and entirely by chance, such that each individual has the same probability .In this technique, each member of the population has an equal chance of being selected as subject. The entire process of sampling is done in a single step with each subject selected independently of the other members of the population. Simple random sampling is a method used to cull a smaller sample size from a larger population and use it to research and make generalizations about the larger group . Simple random sampling is the most basic and common type of sampling method used in quantitative social science research and in scientific research generally.