The Mass of a Proton Is 1

The mass of a proton is 1.00728 amu and that of a neutron is 1.00867 amu.What is the mass defect (in amu) of a Co nucleus? (The mass of a cobalt-60 nucleus is 59.9338 amu.)

A) 27.7830
B) 0.5489
C) 0.5405
D) 0.0662
E) 0.4827