Based on the description and the sample of students chosen in the quiz question, the sampling method used is systematic random sampling. This is indicated by the fact that the students seem to be selected at regular intervals across different classes, rather than being grouped by specific characteristics or completely at random from a single class or grouping.

Here are the details for each type of sampling mentioned in the question for clarity:

• Cluster random sampling: Involves selecting entire clusters randomly, where each cluster is a naturally occurring, heterogeneous grouping, such as all students in a single class.
• Systematic random sampling: Involves selecting members from a larger population at a regular interval after a random start.
• Stratified random sampling: Involves dividing the population into subgroups that share similar characteristics and sampling from each subgroup.

In this example, the student IDs are selected from a larger list (classes A through E, students numbered 1-30), likely at a constant interval, fitting the description of systematic random sampling.

Do you need further details on this or any other questions? Here are some related questions you might find helpful:

1. How do you determine the interval in systematic random sampling?
2. What are the advantages of systematic random sampling over simple random sampling?
3. How would cluster random sampling be implemented in this school scenario?
4. What are potential biases or disadvantages in using systematic random sampling?
5. How do you choose between systematic and stratified sampling for a study?

Tip: When using systematic random sampling, it’s crucial to ensure that the population list is not ordered in any pattern that might bias the sample.