Answer:
A. There are fossils of extinct ancestors of horseshoe crabs and the species is still alive today.
Explanation:
C and D have more to do with how it can be a fossil. It is a living fossil because its ancestors have been found in fossils, yet it continues to live today.
Because it carries a lot of blood to the arteries
Nitrogen is returned to the atmosphere during the nitrogen cycle in a process referred to as denitrification.
<h3>What is denitrification?</h3>
It is a process whereby nitrogen becomes mineralized from nitrogenous compounds. In other words, it is the reduction of nitrates to produce elemental nitrogen which is returned to the atmosphere.
Denitrification is a microorganisms-driven process. The nitrates are made to pass through a series of reactions with intermediate products before finally leading to the production of elemental nitrogen.
More on the denitrification process can be found here: brainly.com/question/13624886
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