ATP is the energy currency of living organism.
It is high energy molecule and provides energy to our body.
The energy releasing equation is
ATP --> ADP + iP + Energy
Where
ATP : Adenosine triphosphate
ADP : adenosine diphosphate
iP : inorganic phosphate
Thus when phosphate bond in ATP is cleaved to give diphosphate and inorganic phosphate energy is released (7.3 kCal approx / per mole)
so answer is
B in the bonds between phosphate groups
The bond is shown in figure as well
