Answer:
a complex organic substance present in living cells, especially DNA or RNA, whose molecules consist of many nucleotides linked in a long chain.
Explanation:
It makes the Earth livable for us creatures. We get protected from the Sun's harmful rays reaching to Earth, which makes Earth feel comfortable. Atmosphere also contains Oxygen and we rely on that everyday.
Human egg cell
But human egg cell is the one of the largest cells in the human body that can be seen with naked eye. i.e we are able to see it without the help of a magnification device. The size of this cell is about 0.12 mm in diameter.
I think I’ll go with C. long dry cold winters
