a. The snow is accumulating at about 3/2 inches per hour.
Step-by-step explanation:
Since the description of the dependent variable is "inches of snow accumulated" and the description of the independent variable is "hours", the meaning of the slope of a line on the graph of inches versus hours is "inches of snow accumulated per hour." In my opinion this best matches answer choice "a" because of the use of the words "accumulated" and "accumulating".
In plain English, the wording of answer choice "d" means the same thing: snow accumulation means snow height. I believe it can reasonably be argued that choice "d" is also a correct answer to this question.
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Please note that the slope of a line on *any* graph has the meaning (unit of dependent variable) per (unit of independent variable).
