The answer is 3
Explanation:
Spleen,a part of the pancreas
Chemically, ATP is an adenine nucleotide bound to three phosphates. There is a lot of energy stored in the bond between the second and third phosphate groups that can be used to fuel chemical reactions. When a cell needs energy, it breaks this bond to form adenosine diphosphate (ADP) and a free phosphate molecule.
It represent a food chain one goes into the other which goes into the other which goes into the other.