Read the passage below and choose one correct answer for each question.

Distant education is a rapidly developing approach to instructions throughout the business. The approach has been widely used by business, industrial, and medical organizations. For many years, doctors, veterinarians, pharmacists, engineers, and lawyers have used it to continue their professional education. Recently, academic instructions have been using distant education to reach a more diverse and geographically disperse audience not accessible through traditional classroom instructions. The distinguishing characteristics of distant education is the separation of the instructor and students during the learning process. The communication of the subject matter is primarily to individuals rather than groups. As a consequence, the course content must be delivered by instructional media. The media may be primarily printed, as in the case of traditional correspondence course. Audiocassettes, videotapes, videodiscs, computer-based instructions, and interactive video courses can be sent to individual students. In addition, radio, broadcast television, telelectures, and teleconferences are utilized for “live” distant education. The latter two delivery systems allow for interactive instructions between the instructor and students.

Question: The striking characteristic of distant education is that ______.