An error is that the scientist did not control their variables. They had one group of people playing the game at 6, and another group playing at 12. This means that other things might have affected the scores other than what was being tested, which was caffeine.
Answer:
"It is the enzyme that breaks down acetylcholine in the synaptic cleft, ending stimulation of the muscle fiber. -It is the type of receptor found in the motor end plate that binds acetylcholine, initiating an electrical impulse."
Explanation:
In animals and plants, there are two pairs of chromosomes - one set from a male and the other set from a female. But occasionally, the original fertilized cell doesn't quite divide correctly and more than two sets arises. The fertilized cell continues to divide with the result that all the cells have the extra set of chromosomes. This happens much oftener in plants and the plant will be sterile and can't form seeds.
A, B, and C make no sense
A makes no sense because Methane is lighter than air, and so the Methane would stay higher in the atmosphere, so it would not seep into the ground, it would remain in the air.
B makes no sense because Burning fossil fuels causes air pollution by increasing the amount of carbon dioxide in the air. the only way that carbon dioxide could pollute water is if it is combined on a molecular level, plus carbon dioxide does not inhibit the process of water being evaporated by the sun.
C also makes no sense because Deforestation causes acid rain by increasing carbon dioxide not decreasing carbon dioxide in the atmosphere.
so therefore by elimination your answer is D
