It will be the year of 2018
B is your answer. it is chemical.
The answer is commensalism.
The complete answer is: The ecological relationship between organisms where one benefits and the other is not affected is commensalism.
There are four kind of ecological relationships between two organisms: mutualism, amensalism, parasitism, commensalism.
In mutualism the two organisms benefit from each other.
In amensalism one organism in unnafected and the other is harmed.
In parasitism one organism is benefited ant the other harmed.
<span>B. Serve a different function I think</span>
Image result for describe the 4 chambers of the heart
The right ventricle pumps the oxygen-poor blood to the lungs. The left atrium receives oxygen-rich blood from the lungs and pumps it to the left ventricle. The left ventricle pumps the oxygen-rich blood to the body