Answer:
D
Explanation:
At a national park in Wyoming, there was already 84 inches of snow on the ground.
Then, snow fell during a snowstorm at a rate of 1.5 inches per hour for 12 hours.
The linear function which describes this situation is

where x is the number of hours since the snowstorm began, y is the number of inches of snow on the ground.
For the linear function

the slope is m and the y-intercept is b.
Thus, the slope of this linear function is 1.5 and the meaning of the slope is 1.5 inches per hour and the y-intercept is 84 inches.