B. Is the best logical answer. my bad if not right.
<span>When we are talking about biogeochemical cycles we are talking about the pathways by which a chemical substance moves through both the biosphere and the atmosphere. There are a number of cycles which come back to the starting point and which can be repeated. Moreover, the very term biogeochemical tells us that there are more than one factor involved. We have chemical, biological and geological factors at play. The circulation of chemical nutrients through the biological and physical world are known as biogeochemical cycles.</span>
Ionic bonds are when atoms gain or lose electrons, giving it a charge (positive or negative), A covalent bond shares electrons and gets a neutral charge.
Therefore, our answer is D.
Final answer:- <span>D. sharing of electrons between atoms.</span>
It helps our blood stream
