I believe the answer is free electrons
At the position of terminal speed the net acceleration of the ball will become zero
As we know that terminal speed will always reach when net force on the ball is zero and its speed will become constant.
So here at this position we can say



now when ball is moving at half of the terminal speed in upward direction then net force on the ball in downwards direction will be


here speed of the ball is half of the terminal speed

then we have


now acceleration will be given as

now we have

downwards
It is letter b which is Global Warming
Answer: Wind follows a pattern because the Earth is spinning in one motion. If we were spinning in one way then another we would have one day go by then the spinning cycle would change and we would have to go through that day all over again, it would not be logical because then we would be in the same season as well, we would be in one season for the rest of our lives until we died.
I don't know if this was helpfull or not but I hope it was somewhat close to helpful? If it is not then please do not report this, I am sorry if this was the least bit helpful.
HAVE A NICE DAY! :)