4. A group of students was surveyed about what types of music each had listened to during the previous week. Students could choose 1, 2, or 3 types of music (Rap, Rock, or Country), or they could respond “none of these music types.” Only 10 students responded with “none of these music types,” and 18 students responded that they had listened to all 3 types. In the figure below, the 8 regions show the numbers of responses in each category.

One region had exactly 8 responses. What type(s) of music did those 8 students respond they had listened to during the previous week?