To find the angle corresponding to 8 years old in the pie chart, we need to calculate the percentage of pupils who are 8 years old and then convert it to an angle.

Total number of pupils = 45 (sum of the values in the table)

Number of pupils who are 8 years old = 6

Percentage of pupils who are 8 years old = \(\frac{\text{Number of pupils who are 8 years old}}{\text{Total number of pupils}} \times 100\)

Percentage of pupils who are 8 years old = \(\frac{6}{45} \times 100 \approx 13.3\)%

Now, to find the angle corresponding to 8 years old in the pie chart:

Angle = Percentage \(\times\) Total degrees in a circle (360°)

Angle = \(13.3\% \times 360° \approx 13°\)

Therefore, the correct answer is option D: 13°.