In this sentence, the word "magnitude" refers to the size or scale of the disaster.
To determine the meaning of the word in italics, "magnitude", we need to consider the context clues provided. In this case, the context clue is that the word is used to describe the disaster. "Magnitude" is often associated with the size, extent, or degree of something. It implies that the disaster was significant or immense. Therefore, we can deduce that the best choice to match the word "magnitude" is an option that conveys the idea of large size or great impact.
