Answer:
the sperm fertilizing the egg
Explanation:
The answer is vitamin D. This is actually a group of vitamins of similar molecular structure responsible for facilitating increased absorption of calcium, magnesium and phosphate from the gut. The most important of the vitamin D compounds are vitamin D3 and D2. While vitamin D can be obtained from your diet and supplements, the major source of vitamin D is from a chemical reaction dependent on skin exposure to the sun.
The answer is carbon dioxide bro thats so easy and you could just look it up
