I believe the answer is C. Positive, since it is a sustainable plan to use a renewable source hope this helps :)
The probability he finds the trait in none of the dogs
Gravity acts to accelerate the ball downward, and air resistance acts in a way to slow the ball along it's instantaneous velocity (no matter which way it's moving air applies a force in the opposite direction)
It has to due with numbers so I would say the last one!
