Answer:
According to the “hygiene hypothesis,” the problem with extremely clean environments is that they fail to provide the necessary exposure to germs required to “educate” the immune system so it can learn to launch its defense responses to infectious organisms. Instead, its defense responses end up being so inadequate that they actually contribute to the development of asthma.
Explanation:
Cacti grow in the desert, which is a very hot climate. Not the best for both gaining and maintaining water supplies, due to the fact that water becomes vapour very quickly in conditions such as a desert (unless we're talking about polar deserts).
Keeping their stomata closed during the day stops water vapour from escaping their cells. While this does inhibit growth and stop new water molecules from entering, it allows the cactus to maintain a healthy amount of water within itself.
Step- by - step - explaination
I Think The answer is b I hope it helps