Select the TWO options that are TRUE statements about survey sampling. Select one or more: In cluster sampling, each cluster should ideally be, as far as possible, a representative cross- section of the whole population. O Cluster sampling requires a complete list of the whole target population before the sampling can begin. Stratified sampling generally decreases costs compared to simple random sampling. In cluster sampling, it is always best to confine the sampling to one cluster. Many well-planned surveys use both stratification and clustering.