Based on the information given, it can be deduced that a stratified sampling method was used.
It should be noted that a stratified sampling method was used by Dianne. This is a method where large amounts of data are divided into smaller groups and then, samples will be chosen for examination.
From the complete question, the justification is that Dianne chose a sample that isn't based on probability as the samples are chosen at random. She wanted to know the relationship between the academic performance of students and the new learning modalities.
Learn more about sampling on:
https://brainly.com/question/17831271
