Based on the context of the sentence, the word "magnitude" is being described as "hard to imagine." Therefore, the best match for the word "magnitude" is "size" or "extent."
To determine the meaning of the word "magnitude" in this sentence, we can look at the context clues. The sentence mentions that the magnitude of the disaster is hard to imagine. The word "hard to imagine" suggests that the disaster is of a large or significant scale. From these context clues, we can infer that "magnitude" refers to the extent or size of the disaster.
