Answer:
O2 is the correct answer.
Step-by-step explanation:
O2 species will have the strongest mass shift on a magnetic susceptibility balance because if the species is stronger paramagnetic, it will have a higher mass shift.
O2 species is paramagnetic, and oxygen atoms with two unpaired electrons are paramagnetic, unpaired electrons rotate in the same direction, which raises the magnetic field force that reason it will have the strongest mass shift on a magnetic susceptibility balance.