Let's see the child's shoulder height with each part of the statements.
• A child stands in line at the base of the ladder for a piece of playground equipment
The shoulder height is a few feet from the ground (child's original shoulder height). The graph should NOT start at 0. It should start at original shoulder height. The child stands at this position for some time.
• The child then climbs the ladder and plays in the area between the ladder
The climbing part models the height of the shoulder as going above. The graph should be sloping upwards, here.
The playing time in the area between the ladder is the same height of the child. So, a flat graph here.
• "...going down the slide"
This part, he goes down. So, the graph would slope downwards.
Now, looking at the answer choices, we can immediately eliminate 2nd and 3rd choice since they start at 0.
From First and Last choice, the correct answer is the first choice because it shows the "flat" part at the starting which corresponds to the time the child is waiting to go up the ladder.