The graph shows the depth of water, in feet, of a water tank over a certain amount of time, in minutes.

graph with the title water tank with the x axis labeled time in minutes and the y axis labeled depth in feet, with a line segment from 0 comma 0 to 40 comma 5, a line segment from 40 comma 5 to 60 comma 5, a line segment from 60 comma 5 to 100 comma 4, a line segment from 100 comma 4 to 140 comma 4, and another line segment from 140 comma 4 to 180 comma 0

Part A: Identify the interval(s) where the graph is increasing, decreasing, and constant. (3 points)

Part B: What are the domain and range of the relation? (3 points)

Part C: Does the graph represent a function? Explain your reasoning. (3 points)

Part D: Write a detailed description of the graph using the real-world scenario and the information from Part A. (3 points)