Answer:
Cluster
Step-by-step explanation:
Random: Each element in the population has an equal probability of selection, and each combination of elements has an equal probability of selection. For instance picking a picking name from a hat.
Stratified: Divide population into groups called strata that differ in important ways. For instance, for a population of a state, male and female strata. for people working in a city, resident and non-resident strata
Systematic: Each element has an equal probability of selection, but combinations of elements have different probabilities
Cluster: this is a form of random sampling. Population is divided into groups, usually geographic or organizational