Four students did a survey to find the soda flavor sixth-grade students prefer. The table below shows the method each student used to conduct the survey: Student Method Trey Asked 100 students at random from his seventh-grade class what their favorite soda flavor is Jesse Asked 100 sixth-grade students at random what their favorite soda flavor is Nita Asked 100 eighth-grade students at random what their favorite soda flavor is Ruben Asked 100 third-grade students at random what their favorite soda flavor is Which student's survey not biased?