Answer: Stratified Random sampling
Explanation:
Stratified Random sampling simply refers to a sampling technique or strategy whereby random selection of observation of samples are made from a population or larger sample by first arranging or splitting the population of interest into smaller groups or separate catagory based on a certain criteria or criterias. Random samples are then taken from each of the groups also called strata. This technique is aimed at ensuring a more even distribution of samples across the various available groups within a population of interest. In the scenario above the stratas or groups are ; Sophomores, Junior, Senior and freshmen.