Answer:
A. The graph of the stock value would start at a low point on the left side of the graph and gradually increase in value as it moves to the right. The line representing the stock value would start to level off and then suddenly drop, representing the quick decrease in value. The line would then level off again and stay the same for the rest of the day.
B. If the stock gradually decreased during the middle of the day, the line on the graph would start at a high point, gradually decrease in value, and then level off.