What is the answer to this

Which of the following systems in absorbing oxygen and releases carbon dioxide

Prior to the development of dna fingerprinting, blood type could be used to determine possible parentage. although it might prove someone was not a parent, it could not show if someone was positively the parent, only that he or she might be a parent. which of the following is a true statement that can be made about parentage based on blood typing?

Resperation is a way to release carbon back into the atmosphere