Answer:
A. "The first fire to break out after the quake was at a Chinese laundry across the street from a firehouse."
Step-by-step explanation:
In any cause and effect situation, the effect is the result of the cause. The cause is the reason of why the incident happened while the effect is what happened.
So, considering the paragraph from "The Great San Francisco Fire", the cause and effect structure can be seen in the sentence "the first fire to break out after the quake was at a Chinese laundry across the street from a firehouse". This sentence provides the cause of the fire and also the effect after the fire, which couldn't be contained or curtailed due to the unavailability of water in the water mains, which had been destroyed by the earthquake.