A researcher wanted to estimate the average amount of money spent on extracurricular activities per school in a certain region. The researcher randomly selected 20 public schools and 20 private schools in the region to use for a sample. Which of the following best describes the type of sample that was taken?

In a stratified sampling strategy, we randomly select members from certain strata, or groups that share characteristics.

A cluster sample might be the second best choice here, but the clusters would have to be from similar populations, not different ones.