The graph shows the height of a hiker above sea level.

The hiker walks at a constant speed for the entire trip. What are the variables? Describe how the variables are related at various points on the graph.
A. The variables are height and time. For the first part of the graph, the height is increasing slowly, which means the hiker is climbing a steep incline. Flat parts of the graph show where the elevation does not change, which means the hiker stopped to rest. The steep part at the end of the graph shows that the hiker is descending a gentle slope.

B. The variables are height and time. For the first part of the graph, the height is increasing slowly, which means the hiker is walking up a gentle slope. Flat parts of the graph show where the elevation does not change, which means the trail is flat here. The steep part at the end of the graph shows that the hiker is descending a steep incline.

C. The variables are height and time. For the first part of the graph, the height is increasing slowly, which means the hiker is climbing a steep incline. Flat parts of the graph show where the elevation does not change, which means the trail is flat here. The steep part at the end of the graph shows that the hiker is descending a steep incline.

D. All of the above.

B) The variables are height and time. For the first part of the graph, the height is increasing slowly, which means the hiker is walking up a gentle slope. Flat parts of the graph show where the elevation does not change, which means the trail is flat here. The steep part at the end of the graph shows that the hiker is descending a steep incline.

Explanation:

The variables are marked on the graph. Time is marked along the x-axis, which means it is the independent variable. Height is marked along the y-axis, which means it is the dependent variable.

The first part of the graph rises slowly. This means the elevation does not change much over the time; this would be consistent with a gentle slope being climbed.

The flat areas are where the elevation does not change. This would be consistent with the hiker resting.

The steep decrease at the end shows that the elevation goes down quickly. This is consistent with the hiker climbing down a steep slope.