Which of the following conclusions is valid? A A random sample of middle school students shows that 10 students prefer pop music, 15 students prefer hip hop music, and 25 students prefer no music while they study. It can be concluded that half the students prefer no music when they study. B The 7th grade Algebra class is surveyed to determine the destination of the 7th grade class trip. Out of the 20 students, 14 chose Washington, D.C. The principal concluded that 70% of all the 7th graders preferred Washington, D.C. as the class trip destination. C An email was sent to students at their home asking which flavor of water they would like to see in the school vending machines. Fifteen students responded. Five chose berry, five chose grape, and five chose no opinion. The principal concluded that 13 of all of the students had no preference as to which water flavor should be in the vending machines. D Customers at a sporting goods store are asked to determine their favorite TV show. Thirty customers preferred watching football. Ten customers preferred a reality show. Ten customers preferred the nightly news. It can be concluded that 60% of people prefer football.