A survey was administered to parents of high school students in a certain state to see if the parents thought the students' academic needs were being met. To select the sample, the parents were divided into two groups— one group of parents who live in cities with populations of more than 100,000 and the other group of parents who live in cities with populations less than or equal to 100,000. A random sample of 100 parents from each group was taken. Which of the following statements about the sample of 200 parents is true?

It is a convenience sample because the sample of parents was easily obtained.

It is a stratified random sample because parents were randomly selected from each group.

It is a random cluster sample because parents were randomly selected from each group.

It is a systematic sample because the parents were systematically divided into two groups.