To add the fractions \( \frac{13}{15} \) and \( -\frac{4}{15} \), you can combine the numerators since they have the same denominator:
\[ \frac{13}{15} + \left(-\frac{4}{15}\right) = \frac{13 - 4}{15} = \frac{9}{15} \]
Next, you can simplify \( \frac{9}{15} \) by dividing both the numerator and the denominator by 3:
\[ \frac{9 \div 3}{15 \div 3} = \frac{3}{5} \]
So the answer \( \frac{9}{15} \) simplifies to \( \frac{3}{5} \).
However, if we only consider the original result \( \frac{9}{15} \), the correct selection from your provided options is:
- \( \frac{9}{15} \)
Thus, you can choose \( \frac{9}{15} \) or simply state the answer as \( \frac{3}{5} \).