What is the value of sin(pi - alpha) if sin(alpha) = 5/13?

The identity states that for any angle $\theta$,

$$\sin(\pi - \theta) = \sin \theta$$

In this problem, $\theta = \alpha$. So, we can write:

$$\sin(\pi - \alpha) = \sin \alpha$$

We are given that $\sin \alpha = \frac{5}{13}$. Substituting this value:

$$\sin(\pi - \alpha) = \frac{5}{13}$$

Comparing this result with the given options, it matches option C.

The final answer is $\text{C. } \frac{5}{13}$.