What are the differences and similarities between cluster and stratified sampling?

Select ALL right answers below:

The stratified and cluster methods do not have similarities.

Similarity: Both uses random selection.

Difference: Not both consider grouping the population.

Difference: Stratified is used for samples smaller that 30. Cluster is used for samples over 30 subjects.

Both sampling methods are exactly the same.

Similarity: Both generates exactly the same sample.

Similarity: Both consider grouping the population.

Difference: In stratified sampling, the subjects are grouped based in its characteristics. In cluster sampling, the subjects are grouped based in its location.