Kinematic Graphing - Mission KG2 Detailed Help

The motion of an object is depicted by a position-time graph. Various time intervals during the motion are depicted by a letter. During which time interval is the object moving with the greatest average speed?
Position-Time Graphs:
Position versus time graphs represent changes that occur in an object's position with respect to time. The slope of the line is the velocity (change in position divided by the change in time) of the object.

The slope of the line on this position-time graph represents the velocity of the object. The velocity can be thought of as a speed with a direction. The time interval during which the speed is greatest is the interval that has the greatest slope - either upward or downward. To answer this question, eyeball the graph to determine the time interval during which the slope is greatest.