Answer: A. The stone thrown upward spends more time in the air.
Explanation:
The stone thrown above the horizontal has an initial vertical speed, whose direction is opposed to gravity. It means that it decelerate first before accelerating in the direction of gravity. Where the stone thrown below the horizontal has an initial vertical speed in the direction of gravity, so there is no deceleration.
In consequence, the stone thrown upward spends more time in the air. Correct answer is option A.