Final answer:
The basketball's acceleration while moving upward on a parabolic path is -g, which translates to an acceleration of 9.8 m/s² downward.
Step-by-step explanation:
When a basketball is thrown upward along a parabolic path, the only force acting on it in a vertical direction (ignoring air resistance) is gravity. Therefore, the acceleration of the basketball while moving upward is g in the downward direction. The correct answer is d) −g, upward, when considering the upward direction as positive. This means that the ball is accelerating downward at a rate of 9.8 m/s², which is the acceleration due to gravity represented by the symbol ‘g’.