For estimation of the mean of a variable, which of the following sampling plans generally leads to a sampling variance larger than the sampling variance of a simple random sample without replacement? Response choices:

• A: Stratified simple random sampling, where the stratification variable is correlated with the variable of interest
• B: Two-phase sampling with simple random sampling at both phases
• C: Cluster sampling with more than one unit per cluster and where units within clusters are homogeneous
• D: Probability proportional to size sampling with size defined by a variable correlated with the variable of interest
• E: Systematic sampling where the units on the frame were ordered at random.