Final answer:
The question about the speed of the plane is unanswerable with the information given; a specific rate of distance increase was omitted, making it impossible to determine the plane's speed.
Thus, the correct option is A.
Step-by-step explanation:
The question asks about the speed of a plane, but the provided information about the rate of increase in the distance between the plane and a person is insufficient because the actual rate in feet per second (ft/sec) is missing from the question.
Thus, the correct answer would be (a) Insufficient information provided.
In the context of the examples provided, calculating the final velocity of a plane that is decelerating, or assessing the velocity and acceleration of moving objects, requires specific numerical values, which have not been provided in this instance.
Therefore, the use of Example 4.1.2 alone in the question does not allow us to determine a specific value for the plane's speed or whether that speed is constant or decreasing.