The table shown summarizes the number of books read by each of the 30 participants in a summer reading program.
| Number of books | Number of participants |
|---|---|
| 1 to 3 | 5 |
| 4 to 6 | 8 |
| 7 to 9 | 10 |
| 10 to 12 | 4 |
| 13 to 15 | 3 |
Which of the following could be the median number of books read by the participants in this program?
5
6
8
10
