A friend of yours in your intro stats class obtains permission to randomly sample the University student body to conduct a satisfaction survey on some recent changes to the enrollment process. She randomly samples 50 freshmen, 50 sophomores, 50 juniors, and 50 seniors. This is an example of a?

Stratified data

Step-by-step explanation:

The given data in the question is an example of a "Stratified data"

A Stratified data is type of sampling of data or the random samples in which the collected data is divided into the sub groups of the same type or the same category.

Also,

The sample size of the subgroups in the Stratified data remains the same for every subgroup.

Here, the subgroups are

freshmen

sophomores

juniors

seniors

and the each have same sample size i. e 50