The graph shows y as a function of x:

Graph of x against y shows 4 segments. Segment A is a horizontal line parallel to the x-axis. Segment B is a slanting straight line going up. Segment C is a horizontal line parallel to the x-axis. Segment D is a slanting straight line going down that touches the x-axis.
In which segment is the function decreasing? (5 points)

A

B

C

D

The function is decreasing in Segment D, where the slanting straight line is going down and touches the x-axis.