Final answer:
Immediately after the rope is cut, the block experiences free fall, which means it will move upward with decreasing acceleration until it reaches the highest point and then descends with increasing velocity.
Step-by-step explanation:
The question involves a scenario in physics where a system, in this case, a block, is initially moving and accelerating upward. Once the rope is cut, the forces acting on the block change dramatically. The upward force provided by the tension in the rope is no longer present, and the only significant force acting on the block is the force of gravity. Therefore, the correct description of the motion of the block immediately after the rope is cut is that the block experiences free fall.
During free fall, the only acceleration acting on an object is the acceleration due to gravity, which is approximately 9.80 m/s² downward. This means that the block will move upward with decreasing acceleration until its velocity reaches zero, at which point it will begin to descend with increasing speed. Therefore, the block does not maintain a constant velocity (disqualifying option A), it does not accelerate upward (disqualifying option B), and it is not accelerating with increasing or constant acceleration (disqualifying option C).