Final answer:
The correct answer is D) Delta, as skydivers assume a position similar to the shape of the 4th letter of the Greek alphabet, Delta, when in freefall. This helps them to control descent and reach terminal velocity where acceleration decreases to zero.
Step-by-step explanation:
In freefall, skydivers assume a position to help them control their descent and to achieve terminal velocity. The delta position, or the 'spread-eagle' position, is similar to the shape of the 4th letter of the Greek alphabet, Delta (Δ). Delta (D) is the correct answer to the question: in freefall, skydivers assume this position, or the 4th letter of the Greek alphabet. When skydivers reach terminal velocity, the drag force due to air resistance equals the force of gravity on the diver, and their acceleration decreases until it is near zero, meaning they fall at a constant speed.
The shape of the graph of the magnitude of acceleration versus time for a falling skydiver would show a decreasing curve that approaches zero as the skydiver reaches terminal velocity. The graph of the magnitude of velocity versus time would increase rapidly at first and then level off as the skydiver approaches terminal velocity. Finally, the graph of the magnitude of displacement versus time would resemble a parabolic curve, reflecting the increasing velocity until terminal velocity is reached, after which the displacement increases linearly over time.