In a Large High School, the 25 Students Who Scored

In a large high school, the 25 students who scored highest on an English pretest were placed in a special class. At the end of one semester, they were given another English achievement test. The mean grade-level equivalents were compared for the two tests. This is an example of a:

A) one-group pretest-posttest design
B) randomized control group pretest-posttest design
C) time series design
D) static group comparison design