Hi i know the answer is rna but which number represents rna on the diagram?

A. The pump refers to the heart, which with each pulse beat, a certain amount of blood volume, with a certain frequency of time, this impulse through the arterial vessels and receiving flow through the venous vessels, the tubes in the respiratory system enter air from the outside to absorb oxygen in its most proximal part and then extract the gas residues in the same way to the outside.

B. The open system in the respiratory system is necessary to maintain a balance between the necessary gas flow and waste, in the circulatory system it is necessary in a closed system to allow the pressures to be kept constant by regulating the volumes to different parts of the organism.

The differences between liquids and gases are that they are different states of aggregation, liquids have a defined volume, gases do not, have different boiling points, kinetic energy is less in liquids than in gases, the liquid exerts less pressure than that of gases.

C. The respiratory pump is in charge of the movement of gases in the body and the heart pump is in charge of the movement of liquids, the difference is necessary to maintain two systems necessary for the vital functioning of the body, which requires the entry of oxygen and the carbon dioxide gas outlet as well as maintaining circulation so that the blood in contact with the tissues can carry nutrients and extract waste, thus keeping the body alive.