A. Water being pumped in and out of guard cells.
Answer:
<em>The correct option is B) 5-10%</em>
Explanation:
We have seen and depicted various scenarios where we see how different changes arise and dominate the world. Social scientists suggest that as low as 5-10% people of a population are enough to bring about a change because people tend to copy what others are doing. Same goes for countries of the world. Each new popular technique which is learnt by one country tends to become popular and learnt by other countries. For example, the usage of a social app starts with a few members of a population using it and with time it becomes popular in the whole world.
You didn't put any answer choices, but air and water are generally the greatest.