A number cube is rolled 20 times and the frequency of each result is recorded in this table.
| (Observed) | (Expected) |
| (Event) | (Frequency) | (Probability) |
1 | 1 | 1/6 |
2 | 2 | 1/6 |
3 | 8 | 1/6 |
4 | 3 | 1/6 |
5 | 3 | 1/6 |
6 | 3 | 1/6 |
According to the table, what is the experimental probability in simplest form that the number cube shows 5?
A. 1/20
B. 1/10
C. 3/20
D. 1/6