I'm taking a test and have to guess the right answer to the question after the article. Article: Today in schools, it's not unusual for students to sit in the same kind of desks in the same kind of classrooms as their parents did. Schools have made progress by making use of computers and PDAs in the classroom, yet one design company believes that changes are needed, so they describe what a future classroom may look like. "Kids are being taught to sit at these wooden desks that are basically designed for writing," said Mark Dziersk, the senior vice president of the design. "They're being lectured in a structured environment." The solution is a "customizable education system" called Gooru that reorganizes the classroom and replaces books, desks, pens, and so on. The three-part technology system consists of an interactive PDA called the GooBall, a backpack and a removable LCD screen for each student. Students can sit, stand or lie down when using the devices, and are not limited to desks. The idea was presented at last month's South by Southwest Interactive Conference. While some educators think the idea is interesting, they doubt whether schools will pay for the expensive and complicated system. The GooBall is an interactive communication device with six layers of learning software. The device monitors a student's heart rate and body temperature and uses GPS to track where they are. It includes instant messaging, a compass, a watch, and a topic-specific alert system that directs a student to related articles and books about whatever they are studying. Students can also choose an animal icon to show their personality. The backpack houses the main power supply for the system and holds some personal items. The pocket keeps items locked tight with a fingerprint security zipper. The portable screen functions like a laptop, providing wireless Internet access and streaming video. It also has a touch screen interface. "I think it's an excellent idea," said Gary Tankard, a sixth-grader who has seen the prototype . "I'm sure that 90 percent of kids would really like to have it." Question: From the passage we can infer that _ . Options: A: students must use the mouse to operate the device B: the device is very cheap to buy C: students don't need a key to unlock the device D: the device will be widely used in schools
The answer to this question is:
C