Answer: C.) The lack of worker safety at the factory.
Step-by-step explanation:
C.) Although it may say, "the cause," the text states, "Most factories were housed in brick buildings that were overly hot in the summer and extremely cold in the winter." Another part of the text states, "The floors were crowded with people and equipment." These pieces of the text are important because heat and crowds are common causes of flames, which can lead to the inference that C is the answer as if the factories weren't as hot and as crowded, the fire would not have happened.