Answer:
The unit of atomic mass is Amu.
(B) is correct option.
Step-by-step explanation:
Atomic mass :
The mass of a single atom of a chemical element.
An atom made by the proton, electron and neutron.
One atomic mass unit is explained by one by twelve of the mass of a single carbon - twelve atom.
We know that,
Gram is the unit of mass in C.G.S unit.
Amu is the unit of atomic mass.
Pound is the unit of mass in F.P.S units.
Hence, The unit of atomic mass is Amu.