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.