Which scenario is an example of irony?

C. A tow truck sits stranded on the side of the road with a flat tire.  

Explanation:

In this case, irony refers to a situation in which the result is very different from the one anticipated by the reader. It is evidenced by the difference between appereance and reality.

Here a tow truck has a flat tire, it is ironic because those trucks are usually used to drag vehicles that suffered a malfunction away from the road. It is not serving it's purpose, it is in a situation where it's  primary function is the only one that can help it.